Frequently asked questions
We answered some of our customers most asked questions the best we could.
If you cannot find the information needed on our website feel free to get in contact by calling us on 01288 377337
or emailing info@r-wall.co.uk
Why R-WALL?
Why choose R-WALL over other ICF systems? R-WALL combines the strength of high-performance XPS insulation with the simplicity of a non-modular design, creating one of the most versatile and high performing ICF systems available. The stronger XPS insulation provides enhanced durability, moisture resistance and long-term thermal performance, while the non-modular system enables faster installation and simpler construction. Combined with expert support and a growing portfolio of successful projects, it's easy to see why more self-builders, developers and contractors are choosing R-WALL
How quick can an R-WALL house be built? Build times vary depending on the size and complexity of the project, but R-WALL is designed for fast construction. We've seen bungalows assembled and poured in as little as 8 days, and an 8m × 8m extension built and poured in just 3 days. Its non-modular design and simple installation process help reduce build times and get projects completed faster
How energy efficient is an R-WALL home ? R-WALL homes are designed to deliver exceptional energy efficiency through smarter insulation, airtightness and thermal performance. Studies have shown that ICF homes typically require 32% less energy to cool and 44% less energy to heat compared to timber-frame homes built to the same energy efficiency standards. When combined with technologies such as solar panels, air source heat pumps and MVHR systems, R-WALL can achieve outstanding results. One R-WALL home built in 2023 using our under-slab insulation system and Ultimate formwork became energy positive, generating more energy than it consumed. The homeowner's annual energy cost? None, they actually earnt money by living in it! For more information, search for the Birdsong Self Build project
How environmentally friendly is R-WALL? R-WALL is designed with sustainability at its core. Manufactured entirely in the UK, R-WALL is made from 93% recycled plastics, with production taking place just an hour from our head office. The manufacturing facility is powered through anaerobic digestion, generating renewable energy from agricultural waste and helping to achieve a net-zero production process. The XPS insulation used within R-WALL is produced using innovative technology that utilises industry waste COâ‚‚ as the blowing agent. Manufactured using renewable wind energy, the insulation has achieved an A-rating in the BREEAM Green Guide, a Global Warming Potential (GWP) of less than 5 and an Ozone Depletion Potential (ODP) of zero. R-WALL's Non-modular design means the entire system is 100% recyclable at the end of its life. Off-cuts generated during construction can be reused within the system, meaning R-WALL generates no landfill waste
What happens after i request a quote? Once we receive your quotation request in the correct format, it is passed to our technical drawings and quotes team for review. They will assess your plans and prepare a detailed quotation covering all required R-WALL formwork. Delivery costs will also be provided separately but are not included within the quotation itself. Once completed, your quotation will be emailed to you along with a quote acceptance form should you wish to proceed. Quote turnaround times can vary depending on workload, but we typically advise allowing around two weeks to receive your quotation. If you haven't heard from us after that time or need quotations sooner, please feel free to give us a call—we're always happy to help.
How long does an R-WALL building last? R-WALL is built to last, with an approximate expected lifespan of 100 years or more At its core is concrete, one of the most durable building materials available, which continues to gain strength as it cures over time. The combination of concrete and high-performance XPS insulation creates a robust, long-lasting structure designed to withstand the demands of modern living for generations. ICF buildings have also demonstrated exceptional resilience, with some structures proven to withstand winds of up to 200mph and wind-borne debris travelling at speeds of up to 100mph.
Cost & Finances
Is R-WALL cheaper than traditional construction? In many cases, yes. The cost of building with R-WALL is often comparable to, or even lower than, traditional construction methods. As energy efficiency standards continue to rise, traditional construction methods often require additional materials and labour to achieve the same level of performance that R-WALL delivers as standard. Beyond the initial build cost, R-WALL homes can offer significant long-term savings thanks to faster construction times, reduced labour requirements and exceptional thermal performance. Lower energy consumption means lower running costs throughout the life of the building. In fact, one of our customers built a home so energy efficient that it generates more energy than it consumes, meaning they actually earn money by living in it. You can learn more about this project by visiting the Birdsong case study on our Projects page.
Can I get a mortgage on an R-WALL build? Yes. Mortgages are available for R-WALL homes, and many lenders are happy to lend on ICF construction. Historically, the Council of Mortgage Lenders recognised ICF as a standard form of construction where the system held appropriate UK certification, such as a BBA certificate. Today, mortgage lending decisions are made by individual lenders based on their own criteria and risk assessments. This applies to all forms of construction, including traditional masonry, timber frame and ICF. As a result, it is always advisable to discuss your project with your chosen lender or mortgage advisor at an early stage, regardless of the construction method you intend to use. A recent study conducted by a mortgage broker found that the majority of lenders approached were happy to lend on R-WALL ICF homes. A small number requested additional information before approving, but no lenders refused lending during the study. For assistance, please visit our Useful Contacts page where you'll find details of mortgage advisors familiar with R-WALL and ICF construction
Can you obtain equity release on R-WALL? Yes you can obtain equity release on R-WALL homes
Design & planning
Do we need a certain architect to design our R-WALL build? No. Any architect can design a building using R-WALL, and there is no requirement to use a specialist architect. To help architects get the most from the system, R-WALL offers Continuing Professional Development (CPD) training sessions that provide a deeper understanding of the product, its capabilities and best-practice design principles. This allows architects to design more efficiently and fully utilise the flexibility and benefits that R-WALL offers. If you would prefer to work with someone who already has experience with the system, we can also recommend architects who have completed our training and have previously designed R-WALL projects. Head to our 'Useful Contacts' page to find out more
Are there any design limitations with R-WALL? No. Thanks to its non-modular design, R-WALL offers exceptional design flexibility when compared to many traditional ICF systems. Using just four core components, R-WALL can be adapted to create virtually any structure, from simple homes and extensions to more complex architectural features. Curved walls, stepped walls, corbels, retaining walls, basements, swimming pools and even ponds can all be constructed using the system. Unlike modular ICF systems, R-WALL is not constrained by fixed block sizes, giving architects and builders greater freedom to bring their designs to life. Whatever your vision, R-WALL provides the flexibility to make it a reality
Can R-WALL reach passivhaus standards? Absolutely. Passivhaus wall U-values are typically 0.15 W/m²K or lower, and R-WALL offers a range of eight different formwork options capable of achieving U-values from 0.14 W/m²K down to as low as 0.09 W/m²K. Combined with the excellent airtightness and thermal performance that ICF construction provides, R-WALL is an ideal solution for those looking to achieve Passivhaus or other ultra-low-energy building standards.
How many storeys can be built? Builds with ICF are limited to 11 meters maximum
Does it need steel? Not usually. R-WALL is designed in accordance with a structural engineer's specification, but in many cases no steel reinforcement is required within the walls other than above openings such as doors and windows. Where reinforcement is required, every R-Tie includes integrated notches for the placement of rebar, ensuring the correct concrete cover is maintained and simplifying installation. Unlike many modular ICF systems, R-WALL's uncongested concrete core makes it easy to incorporate starter bars, rebar and larger steel sections where specified by the engineer.
How thick are the walls? R-WALL walls are available in a wide range of thicknesses to suit both the thermal performance and structural requirements of your project. The overall wall thickness is determined by the insulation specification and the concrete core width specified by the structural engineer. Thanks to the flexibility of the R-Tie system, the concrete core thickness can be easily adjusted to meet different demands. R-WALL wall widths range from as little as 205mm up to 613mm, providing solutions for everything from highly efficient homes to heavily loaded retaining walls and commercial structures.
Is R-WALL suitable for extensions? Absolutely. R-WALL is an excellent choice for extensions and can easily be tied into existing structures using wall starter kits or rebar fixed into the existing building. Its non-modular design allows it to adapt to virtually any extension layout, making it suitable for everything from small single-storey extensions to large multi-storey additions. In fact, we've seen an 8m × 8m extension assembled and poured in as little as 3 days.
Can R-WALL be used below ground? Absolutely. R-WALL is arguably the ideal construction method for basements, retaining walls and other below-ground structures. Unlike many ICF systems that use EPS insulation, R-WALL utilises high-performance XPS insulation, which is unaffected by moisture and water and satisfies UK Building Regulations for below-ground applications. This makes it particularly well suited to basement construction where long-term durability and moisture resistance are critical. R-WALL also offers significant structural advantages. Many modular ICF systems can be limited by fixed internal webs and congested concrete cores, making steel placement more difficult. R-WALL's moveable tie system and clear concrete core allow for the easy incorporation of steel reinforcement and mesh where specified by the engineer. The lightweight nature of the system makes it easy to handle and install below ground, allowing substantial structures to be built quickly and efficiently with a relatively small workforce. In many cases, the overall cost of basement construction using R-WALL is significantly lower than alternative construction methods
Construction & Installation
How are gables poured without the concrete falling out? Gables are formed by leaving the top of the formwork 'open' and carefully placing the concrete at the correct slump. The concrete is then poured slowly and in a controlled manner, allowing the gable to be filled safely and effectively without the concrete escaping the formwork. To see the process in action from the perspective of one of our on-site technicians, visit our YouTube channel and search for "Pouring Gables with R-WALL".
What foundations are required? R-WALL can be built on virtually any foundation type, allowing the most appropriate solution to be selected for your project and ground conditions. The most common foundation solution is a concrete slab, however R-WALL can also be used to form strip footings and raft foundations. Thanks to its versatility, the system can be adapted to suit a wide range of foundation designs specified by your engineer.
How does it connect to the foundations? R-WALL can be connected to a wide variety of foundation types using our specially designed Starter Pack system. The Starter Pack is mechanically fixed to the foundation, providing a secure and accurate connection point for the formwork
How do you support it during the pour? R-WALL is supported using our alignment system, which is mechanically fixed to the formwork. The system incorporates twin-threaded props that allow the walls to be accurately adjusted and aligned before and during the concrete pour, ensuring the structure remains plumb and in the correct position. Window and door openings are braced using standard 4" × 2" timber (not supplied by R-WALL) to maintain their shape and dimensions during the pour. As a general rule, the alignment system can be removed 24 hours after the concrete pour. However, timber bracing to larger openings should remain in place for a minimum of one week, or longer where possible.
How do i connect intermediate floors? R-WALL is compatible with any intermediate floor type. A range of standard details for different floor types is available within our Design Library, making it straightforward for architects, engineers and builders to incorporate their preferred floor construction method into the design.
Can it be built in the rain? Yes! R-WALL can be built in all weather conditions. Everyone knows the delays caused in the building industry by the Great British weather however R-WALL is exempt from these delays are the formwork can be built in all safe weather conditions. No more delays just a need for some better waterproofs
Does the concrete need vibrating? Yes, but not as much as you might think. R-WALLs non modular design means it has an uncongested core which allows for greater fill efficiency. When attending pours we bring our own pokers to site in order to ensure there are no voids left in places of congestion such as around steels and openings.
How high can you pour concrete in one go? We usually pour to intermediate floor height, however some bungalows are able to be completed in one pour but conformation will be needed from our technical team prior to booking pours.
Can my builder install R-WALL? Yes. However anyone who wishes to build with R-WALL needs to receive appropriate training by our team. Our on site training means that our team are with you a number of times throughout the build in order to ensure it is being constructed properly. Once a builder has received appropriate training by our team, they are logged in our system and training will not be needed for any future products. If you would prefer to work with someone who already has experience with the system, we can also recommend builders who have completed our training and have previously worked on R-WALL projects.
How does concrete get into the walls? Our preferred method for pouring concrete is with a boom pump. Boom pumps MUST be equipped with a 4-inch reducer and if possible, a 4-inch flexi hose (mud snake) to better control the concrete flow and put less pressure on the formwork. Other methods commonly used for pouring concrete are line pumps, conveyors and in some cases telehandlers with buckets and a competent driver. R-WALL pours MUST be completed in a series of three continuous loops around the building. This method helps distribute pressure more evenly across the system and reduces stress on the formwork compared to pouring one section at a time.
Finishes & Services
How do you attach plaster board? No need to "dot and dab". Plasterboard attaches straight onto the polystyrene, secured by screwing into the R-Rails
How is render applied? Straight onto the polystyrene! Renders such as Silicon or thin coat renders or those recommended by the manufacturer for use on ICF can be applied straight onto the polystyrene. Conventional sand, cement and lime render can be used but must be put onto a render carrier. Please do not use SAS pro rend on R-WALL!
How are services chased into the walls? Quickly and easily! Prior to plaster boarding, electrical services are easily chased into the wall by removing 20-25mm of material from the face of the internal R-Board panel with the use of a hot wire cutter or multi-tool.
Industry recognition
Is R-WALL an ICFA member? Yes as of 2025 R-WALL is officially recognised as a member of the ICFA (Insulating Concrete Formwork Association)
Is ICF a new technology? No. While ICF continues to become increasingly popular in the UK it is a well established building method that has been successfully used for decades. R-WALL Was released in 2020 has seen rapid organic growth since as new customers continue to be satisfied with the product.
Has R-WALL been recognised in any building awards? R-Wall has recently received several major industry awards. It won 'Best Insulation Product' at the 2025 Build It Awards and has been awarded 'Best ICF Home' for the last 2 years. In 2025 it was also nominated for 'Best Eco Home'. A 150 property development built with R-WALL also won 2 awards at the 'International Property Awards'