Retrofit
The Passivhaus Institute developed their EnerPHit design and retrofit methodology in 2015 to enable existing homes to be refurbished to a high quality to achieve good levels of comfort and drastically reduce both energy use and carbon emissions by 60 to 80%. Just imagine having a home that’s not only warm and draught free but has lower energy bills.
Thermographic image of home pre-retrofit. Note: red indicates high heat losses
You may already be aware of the level of energy performance your home currently has, by referring to it’s Energy Performance Certificate (EPC). British homes have an average EPC rating of D but with the agreements reached at COP 26 the UK has a legal obligation of reducing it’s carbon emissions by 75% by 2030 and as close as possible to 100% in Scotland by 2040 and net zero carbon by 2045. England and Wales follow on with 2050 as their target.
As of Spring 2022, Building Regulations rarely mention any requirements for us to improve our homes, however this is likely to change with both Westminster and the devolved Governments considering a carrot and stick approach, with a mix of funding, loans and legislation. At the moment the Energy Saving Trust has grants and interest free loans available to assist in funding the necessary improvements which are coupled with advice on how to obtain this funding and how it must be spent.
As we are Passivhaus Designers and have in-depth experience in retrofitting homes, we are able to advise our clients in achieving the necessary improvements in a cost effective manner. Typical improvements are listed below:
• Adding natural breathable insulation to walls, floor and roofs where possible.
• Reducing air leakage (draughts) to avoid wasting heat.
• Replacing existing windows and doors with high quality Passivhaus certified products.
• Replacing existing gas, oil and direct electrical heating with low and zero carbon alternative.
• Incorporating the latest renewable energy technology
• Using heat recovery ventilation and waste water systems where appropriate.
We can offer our clients the following:
• An initial home visit to view your house and discuss the options with you followed up by an initial Retrofit Strategy report outlining the way forward.
• If or when you undertake the works we would provide you with a fee proposal to undertake the following services:
Test and analyse your home to determine how well is currently performs.
Test a variety of potential improvements to identify which methods are the best and most cost effective.
Compare the results with a number of Standards, including Passivhaus EnerPHit for you to choose from.
Assist you in applying for available grants and loans if required.
Produce a schedule of works together with a step by step programme which could be undertaken in one contract.
Prepare and submit planning and building control applications if required.
Prepare construction drawings and specifications to enable the works to be tendered.
Administer the construction Contract if required.
Carry out the Principle Designer role as required by Health and Safety.
In addition to the above, we would provide you with a Quick Start Guide to assist you in optimising and maintaining the performance of your home over time.
Case Study - Dorran Low Energy Standard retrofit
Dorran bungalows were post-war housing that used reinforced concrete panels in their wall construction. These often had the steel reinforcement close to the surface of the concrete which allowed moisture to oxidise, or rust, the steel. Steel expands when it rusts, so this caused the surface of the concrete to spall and crack. When this happens, this is known as concrete cancer and can cause structural failure of the panels. As a result of this, dorran bungalows, and other types of post-war housing constructed in similar manner, is often not suitable for mortgage borrowing. These quick supply housing solutions were poorly insulated and generally relied on high output heating systems, costing a lot to keep running.
Architeco were commissioned to address the issues with a Dorran bungalow in Barrhead. With the walls being constructed in concrete, the thermal insulation was extremely poor, with damp and other issues being evident. We developed a strategy that would both insulate the walls as well as structurally repair any potential failure of the concrete panels.
By wrapping the whole building in an insulated structural skin, the new external leaf connects into the roof structure protecting against structural failure. The concrete panels have now become internal and offer excellent thermal mass to the house, helping to balance peaks and troughs in temperature variations.
New windows were fitted in the insulation layer, with the whole house clad in larch, dramatically changing its appearance. The attic space was insulated using sheeps wool insulation and the concrete roof tiles were replaced.
With the new insulation, the fireplace and oil boiler became redundant and were removed along with the chimneys.
With Retrofit First fast becoming the preferred approach to sustainable architecture, even the most difficult of buildings offers opportunities to be greatly enhanced and utilised for the foreseeable future, and can be more cost effective than you may think.