Upgrading Existing Homes
Clean Footprint

Clean Footprint (15)

Clean Footprint Ltd aim to deliver energy efficient homes at a cost compatible with conventional construction.


  Two-bed bungalow
Three-bed dormer
Three-bed house
house 200m2
Five-bed executive
house 280m2
What does it cost to build a House in Styro Stone 350mm Neopor with U-values of 0.14 W/m²K
StyroStones only £ 8995.07 £ 9423.60 £ 16,154 £ 19,000 £ 20,000
Volume of concrete 17.9 m³ 19.3 m³ 30 m³ 34 m³ 38 m³
Area of walls 117.5 m² 125 m2 225 m² 250 m² 275 m²
System supply and erect (from DPC) £ 14,687 £ 15,625 £ 28,125 £ 31,250 £ 34,375
* These are ball park figures
Please send us your plans for an accurate caclulation or use our free online Calculation Program
Building Costs - 4.8 out of 5 based on 4 votes

Choosing your ICF

Which ICF?

Which ICF should I use? What is the best ICF? How much does it cost to build using an ICF?

So you have landed on this page to get some information in the hope of assisting you with the decision of which Insulated Concrete Form to build with.

Why I choose StyroStone for the preferred ICF system.

Do you have a bag for life or do you continue to pay 5p every time you shop then throw the bag away.

If you have a choice of car will you pick a Lada or a Rolls Royce , a VolksWagon or a Mercedes. There is a reason some things are cheaper. They are not as good. You get what you pay for.

Do you use a Hoover? A Dyson? or a vacuum cleaner.

It is fact that all ICF's or PIF's were known generically as StyroStones. As building with them became more and more popular many variations emerged on the market.

One of the first questions most people ask is what is the price for building with an ICF?

Surely a better question is what is the cost. There is always someone who will do it cheaper. The price is what you pay however in the long run it can cost you dearly.

In what way will a cheap system cost me more?

Which ICF?If you use a system that comes in flat pack form your labour costs will be accelerated considerably.
It is much more time consuming to put the components together on site.

There is also the risk that ties will inadvertently be left out. There is a greater chance of bursts during the pour.

Some systems have metal ties. These are potential thermal bridges it also means risk of injury on sharp ends and more effort to cut to size.

Some systems have styrofoam ties. These are potential acoustic/fire breaks.

Some systems are less dense and can not take the pressure of mass concrete being poured from hieght. This means more pump visits to pay for and extra labour expense.

StyroStone is a complete system. It comes in factory assembled fully moulded together units thus reducing the possibility of bursts during the pour. There is less requirement for additional timber bracing around windows and doors. It has zero thermal bridging due to hard plastic ties and can provide any U value  requirement by using the VIB STONE-link. The StyroStone 350mm neopor block supersedes Passiv Haus requirements with its 0.147W/m2 U value. It can be filled in 3m high lifts with ease.

Some systems have inferior U values to styrostone https://www.styrostone.co.uk/r-value.html- this is fine for use on outbuildings , swimming pools etc however when self building your dream home surely you will want to eliminate energy bills as far as possible. After all it is pointless having a dream home that you can not afford to live comfortably in.

Consider that you built with a cheap inferior system. Your energy bills continue to rise year on year draining any cashflow. However if you build with StyroStone , your energy bills are minimal. The extra money you save could be used to clear your mortgage off years earlier or you could afford to use the savings towards a holiday a better car or basically better lifestyle.

You may only do a self build once in your life. Build it to your best ability. Build it right. Build it air tight. Build it using energy efficient StyroStone.

Choosing Your ICF - 5.0 out of 5 based on 2 votes

StyroStone® supply scandal

StyroStone® supply scandal

Potential self builders aiming to construct their new dream homes should be made aware of a clever play on words being used by some unscrupulous ICF contractors.

ICF's (Insulated Concrete Forms) also known as PIF's (Permanent Insulated Formwork) have been known generically as styrostones. Building blocks constructed from styrofoam. However as the popularity of this modern method of construction soars so do the inevitable availability of imitations grow.

There are a number of excellent reputable products on the market each with their own merits and also downsides. The original styrostone system was produced in 1950 and named the Iglu-system.
Since then many ICF's have emerged.

StyroStone® are one of the oldest and highly respected companies in the ICF business. Their system has been imitated world wide and variations to the design have enabled any breach of copyright. The family run company are sadly victims of its own success. Nowadays when a prospective client enquires to a construction contractor or ICF supplier “do you build with/ supply styrostone they inevitably reply YES. Of course they are being truthful to a degree, they will build with styrostones -stones made from Styrofoam.
They are not however using the official STYROSTONE® brand. The client may think they are “getting a deal” by not buying off the official web site. Beware! they could be using an inferior product and the client does not know any different. The risks are that the substitute product does not have any accredited certification. The insulation values could be lower or the density of styrofoam much lower than the real thing. The pitfalls are that mortgage companies will not lend on uncertified systems. If the thermal insulation values are not adequate – energy bills will be higher. If the block density is low there is a risk of blow outs during the concrete pour.


In Wales we have a renowned delicacy known as the Clark's Pie http://en.wikipedia.org/wiki/Clark%27s_Pies. It is a pie to die for!
There is an art to eating one of these gems, acquired only after years of practise. Once mastered you would never eat anything but the original Clarke's Pie. Many bakers have tried to copy this delicacy they fail miserably. How do you know you are buying the real thing- it is embossed into the base pastry of the pie “CLARPIE”.
How do you know if you are in fact getting the real deal and buying Styrostone ® ?
Quite simply the real Styrostone® has the logo embedded into the walls of every stone. Each pack of blocks comes on a pallet marked with the StyroStone ® logo.

Do not settle for anything less than real Styrostone's, Like the original pie ,they just won't rest easy on the pallet.

Please be aware that CleanFootprint  Ltd only use the original StyroStone ® products.

StyroStone Supply scandal - 5.0 out of 5 based on 8 votes

Demolish and Rebuild!


Penarth, South WalesMadness by the sea

In the Victorian sea side village of Penarth,(South Wales) also known as Garden by the Sea ,there are rumours spreading questioning the sanity of its residents.
Is it age or maybe the sea air that is effecting their logic? For in Penarth over the last year alone residents of the sleepy seaside village have witnessed no less than four seemingly good houses demolished and rebuilt on the same footprint as the old property.

Are these people crazy? What is the logic in taking down a perfectly good structure?

Victorian Terrace in PenarthEconomics is driving them sane

The truth is that these people have researched well.
Consider, they have just bought a property in an area they love or have lived in it for a long time and don't want to leave the area. Due to the age of the property, it is in need of an upgrade. It will require new windows, doors, re-wire, re-plumb, a new bathroom and kitchen.

When all of this work is being carried out the plaster will be hacked off to renew the services and the floor boards lifted. Undoubtedly their will be unforeseeable damage which the builder will claim EXTRA's for!

Pembroke TerraceThen there is that little bit of re modelling required to modernise the living area. Maybe two rooms into one ? or a small extension and orangery? The roof may be OK for now however it will need attention in a few years and they have been informed by the surveyor that there are signs of wood worm and no felt under the slates.
The amount of work needed dictates that they will have to vacate the property for a few months and further more they have to get the improvements passed through planning control.

They then calculated that after all this work that they will do (probably funded by a top up mortgage or loan) they then have to consider their fuel bills when they finally occupy the old house.

So What is left of the old property before all of these improvements are made? An old shell, a shell that is inefficient energy wise. The new improved property will look superb but will cost a fortune to heat.

20% paid by taxes

Pembroke TerraceThe people in question above have looked more closely into the finances. They realise that to demolish the old house will only take a week. It will only take a couple of weeks to re build completely in STYROSTONE. BUT THE MOST IMPORTANT FACT is that by building it from new they are eligible to reclaim all the VAT @ 20%. They also now have a brand new super insulated energy efficient house that will cost pennies to run. The VAT reclaim along with the disposable income provided by energy savings will more than pay for the cost of the styrostone shell.

Not so crazy

They are now the owners of the most valuable house in their areas.

Older properties were built with much larger gardens than today's properties in order that the occupants could grow their own produce.

Why not stop looking for that small plot tucked away between other properties and look at the viability of buying an older larger house with a big garden and go CRAZY!

Pembroke Terrace Pembroke Terrace

Demolish and Rebuild! - 4.3 out of 5 based on 6 votes

This property has been built on the site of an existing property that was only approx 25 year old.

However it was to building regs of that age.

Augusta RoadThe client gave us a brief of the required renovation program. It involved new windows, rewire, replumb, extend and knock a few rooms into one.

We sat with the client and explained that despite the revamp it would still be in-efficient energy wise. Why not demolish and rebuild exactly how they wanted it in new energy efficient StyroStone. That way they would have a brand new build with all of their wish list and it would be a quicker time scale. Also by building new they could reclaim all the VAT.

That coupled with the fact that they would be forever making savings on their energy bills swung the decision to go for it. Six months later they have their dream home.

This is one of four similar demolish and rebuilds of perfectly habitable properties that we have carried out for clients in the last 18 months. All have been within a 4 mile radius! We must be doing something right.

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Augusta Road - 4.8 out of 5 based on 4 votes

Related Links

Clean footprint are happy to promote ethical companies that share our values, embrace green issues and seek to reduce their carbon footprint where ever possible.





Related Links - 4.6 out of 5 based on 5 votes

Included here are extracts form the media of a recent retro fit project carried out by Clean footprint Ltd

The project in 16 Pultney Gardens, Bath, is particularly significant due to the fact that Bath is aiming to become the retrofit Capitol of the UK .With groups such as Transition Bath and The "Green Doors" initiative in Bristol, the retrofit movement is certainly gathering momentum!

Ozzie and Mary Field have bought a typical Victorian terraced house in Bath. This is a brief description of their on-going journey to 'retrofit their home' and so live more lightly upon the planet.

UpgradingWhy did you choose to upgrade your home?
We are doing a retro refit "because we can".
For us it was the ever-present and clear threat of climate change, particularly in the developing world that was the driving force behind the decision to reduce our carbon footprint.
As we explored the processes further we realised there are many attractive incentives such as the prospect of greater self reliance and reduced fuel bills. As time goes by the price of fuel will go up. We are now on fixed incomes so the proportion of our spending money required for fuel will increase and our spending money will go down.
As we had already begun to downsize it seemed the most logical next step to increase our efficiency.

How did you start the process?
We began by considering building work to allow more sunlight into our new house. The back faces South, yet was in use as a toilet and coal shed. Then we decided to take the opportunity to eco-refit the property. We began by investigating similar schemes which were hard to find. Eventually, we found the precedents and contacts and had all of the necessary information to get the ball rolling.

Research was not easy, for example finding professionals who could explain to us what they could do to assist us. Useful information was obtained from Eco exhibitions and websites such as the Camden project, about a 'Victorian house for the future', and the T-Zero project, an example of a retro fit of a solid walled property.

Choosing the team
Not all building professionals will be capable of undertaking and advising upon such works... You must choose your team carefully and do your research. Clean Footprint was appointed as the main contractor aiming from the beginning to exceed current minimum legal requirements. Indeed, building regulations will be revised upwards in a few years, therefore, the easiest time to consider a full retrofit of your property is when moving or working on your home.

What Measures are you taking?

  •  Insulation not just in the roof space. It is not so difficult to do the walls and under the floor as well. After all it is the most cost effective way of reducing fuel bills.
  •  Air tightness measures around open space and windows.
  •  Mechanical Ventilation and Heat Recovery for controlled fresh and warm air.
What Measures to take  •  A highly efficient gas fire for occasional use.
  •  Solar hot water panels combined with efficient domestic hot water.
  •  A Condensing 'A' rated boiler.
  •  Zoning and advanced heating controls to use heat where it is needed.
  •  Under floor heating as a base to ensure a comfortable temperature.
  •  A wood & multifuel stove for direct space heating.
  •  Triple Glazed windows with argon gas filling to achieve a U-value of 1.0.
  •  A fully glazed south side to allow for solar gain.
  •  Low Energy Light bulbs and appliances.

What progress have you made?
Construction started in March 2010 and building works are now in progress to make the best of the south facing aspect. The eco refit is underway including all measures suggested in the SAP report. The builders are making great progress and we expect to move in by the end of June or at the beginning of July. The journey so far has been an educational and exciting experience.

The inefficient gas boiler and living room fire have now gone and the solar panels are on the roof. The new boiler, tank and related kit are in position, and some radiators in place, with a gadget to deal with Bath's hard water. The walls have now new insulation while in the roof the rafters have been deepened by a couple of inches to take thick insulation board. The contractors have cleaned the removed stone for reuse.

How will this benefit you in the future?
Benefit in the futureAs we are concerned about our negative effect upon the world we are glad to have the chance to reduce our footprint. A good measure of this is the Code for Sustainable Homes which consider the building and life it supports holistically. The ffields are aiming for Level 5 of the energy sections of the code. Overall we hope for an improved quality of living, both for ourselves and, ideally, globally.

This is an idea embodied in the Transition movement principles: moving from an unsustainable way of living and using better the Earth's resources. We are convinced that this is a worthwhile investment; there will be energy savings, lower emissions and a reduction in associated costs.

With energy efficiency and carbon environmental impact going up the ffields are working towards a future for all. This will require additional adjustments to their lifestyle, regarding transport and patterns of food consumption–other aspects of the Transitions movement programme. It fits also with our national policy, the surest way to increase energy security is to design for less energy consumption in the first place. Energy conservation measures, which can result in significant financial savings, higher comfort levels and health benefits for UK citizens.

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South West Built Environment Awards 2011 Winner


The Bath Project - 5.0 out of 5 based on 5 votes

Retrofit and renovation of a Victorian Terrace in Penarth.

Retrofit and renovation of a Victorian Terrace in PenarthThis was an end of terrace which we renovated to improve the energy efficiency and reduce carbon emissions.
We then built a new property on to the end of this in StyroStone which boasts walls , and roof of 0.14 u value. It is made air tight using Siga membrane throughout the roof and a range of Siga tapes and products around windows etc. The whole project supersedes all building reg requirements.

I think it is a fantastic example of Victorian and modern build in harmony alongside each other

This project involved the complete renovation of a Victorian end of Terrace to modern standards.
All that remained of the existing building was the frontal facade and half of the roof! Every wall and floor was removed and replaced with new super insulated walls ans floors and a heavily insulated roof .

Ducts are pre installed for MVHR and the property now has underfloor heating to ground floor and rads to upper floors. The hot water is supplied via an A rated gas condensing boiler. Planning has been granted to build a new unit onto the end of this property. This will commence shortly and the new dwelling will be built to levels in accordance with passive house standards.

The main fabric of the building is to be StyroStone 350mm blocks which will provide a U value of 0.147.
We anticipate fitting solar thermal panels to both properties and introducing thermal stores, rainwater attenuation measures as well as MVHR to ensure that the properties are future proofed.

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Pembroke terrace case study - 4.9 out of 5 based on 7 votes

A project briefing

Project Background
After spending the last 5years living in an eco friendly energy efficient StyroStone property in Spain we moved back into our old property in the UK.
This house was built in a traditional manner out of block work and stone by myself to a high standard, however it was constructed in line with current building reg. Standards (for 1998). After the first month we were alarmed that we had ran out of fuel for our heating for the second time.

At first we thought that there had been a leak in the service pipe or that we had been subject to an act of fuel theft. Only after closely monitoring our fuel use did we realise it was due to the fact that fuel cost had risen so dramatically, that what we had spent, that had previously been sufficient to see us through the winter was now only lasting a few weeks. We decided to commence on a programme of retrofitting internal insulation and other measures to reduce our bills.

Project BackgroundAt the same time my son had purchased a terraced property in the same town which was in need of total renovation. We decided to apply all of the principles of a StyroStone construction to the renovation of this property as well, and thus take the property from a "G" rating to a respectable "B" rating, hence reducing Carbon emissions and energy bills by up to 80%.

Our train of thought was to do as much as possible on a £20,000 budget so that this could be tagged onto the mortgage for a minimum monthly repayment, compared to doing minor upgrades and having to suffer ever increasing energy bills whilst living in this property. This way my son would know what his fixed expenses were and would always have more disposable income on a week in week out basis.


42 Pill Street, Cogan, Penarth was built approx 110yrs ago of solid wall construction. It had since been upgraded by having the front elevation rebuilt in cavity work with 25mm foam insulation. This also applied to the rear annex. The property had originally been a 3 bed, 2 reception no bathroom house however the rear bedroom had been converted to a bathroom.
Gas fires were installed in a poorly constructed rear ground floor kitchen extension, with flat roof, and in the lounge.
The front room floor had been renewed in concrete and screed however the middle room still boasted a suspended timber floor. The wiring was in poor condition. The Existing PropertyThe roof space on the extension and the main building were uninsulated.

The plan was to reduce the size of the bathroom on the first floor and introduce a shower alongside the bath. Make room for a boiler and thermal store and to convert the loft space for use as an additional store space/office area.
Although building regs/planning were not required or applied for, we were to construct everything in accordance with and where ever feasible supersede building reg requirements. This way, should any future occupier wish to use the roof space as a third bedroom, permission could be applied for and approved without problem.

As previously stated our main drivers for retrofitting the property were to reduce fuel bills and carbon emissions by up to 80% and enable my son to live in comfort without paying on an escalating curve.
The priorities were to make the property air tight, super insulate the walls and roof and fit suitable heating systems for space and hot water. This would be via a gas condensing boiler and solar panel. If the budget permitted, we would fit MHRV, however it may, at this stage, be only affordable to pre fit the ducting for this system and add the main unit at a later date.

It was necessary to rewire the property and fit new kitchen and bathroom. The kitchen would be eco friendly and contain "A" rated appliances.
We would also insulate the floors where possible.
Petrofit ProposalsResearch proved that Kingspan K17 phenolic foam backed plaster board were the best option to line the external walls of the property to give the best U value. These boards are a total of 92.5mm thick however due to the size of the rooms, once fitted the loss in space is not noticeable.

Celotex 75mm was used between the roof rafters in conjunction with Web Dynamics TLX silver multifoil for the insulation of the loft space. This would assist in our goal of air tightness. One of the natural by products of building with StyroStone permanent Insulated Formwork, is that being a mono coque structure, it is inevitably air tight.

The work force on this retrofit project were given tool box talks on the how's and why's of making a building air tight. Explanations on how this can be checked and monitored using infra red and thermal imaging, ensured that guidelines were adhered to. Once the team is on board and understand the dynamics, the rest is easy!

By far the simplest and most effective measures that can be taken to reduce fuel bills is to fit insulation to the fabric of the house and make it air tight. The house then performs just like a Thermos flask, it will maintain whatever temperature you have inside it as long as there is no leaks or escape paths for the energy to leave.
If the heat does not escape you do not need to keep burning fuel to replace it , and if you are not burning fuel you are reducing your carbon footprint and saving money at the same time. A true win win situation!.

If you were sat in a room and £5 note blew out of an open window, you would get up and chase it down the road, and yet this in reality, is what we ignore every day that we live in a draughty poorly insulated house! Money escaping through the walls and roof.
Why go to building regs which only suggest the minimum? Why wait for them to change?
Go for the best insulation now and start to save money.
In this economic climate it is a better investment than an ISA.

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Retro Fit and Replicate - 5.0 out of 5 based on 4 votes

Retro Fit Case Studies


Retrofit & replicateRetrofit & replicate
After spending the last 5years living in an eco friendly energy efficient StyroStone property in Spain we moved back into our old property in the UK.
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Pembroke terrace case studyPembroke terrace case study
This project involved the complete renovation of a Victorian end of Terrace to modern standards.
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Pultney Garden case studyThe Bath Project
The project in 16 Pultney Gardens, Bath, is particularly significant due to the fact that Bath is aiming to become the retrofit Capitol of the UK .
View Gallery

Retro Fit Case Studies - 5.0 out of 5 based on 5 votes
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