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Sustainability considerations when you are renovating

By January 12, 2021Knowledge & Tips

At APM we’ve always been interested in looking at sustainability options in our clients’ renovation projects. Until recently, we’ve been put off actually implementing many of these by the apparent difficulty, cost and lack of readily available (and quantifiable) info on the possibilities of doing so in domestic renovations/ retrofits.

One of the main reasons we are working towards building more sustainably is for the creatures that we share the planet with, such as this gorgeous swan above. This lovely shot was taken in Regents Canal by Helen Rayner of Moon Street Studio Photography, the photographer who takes our wonderful project photos.

We are lucky enough to have been introduced to Cath Hassell of, pictured below, who’s been really knowledgeable and inspiring about the increasing number of ways we can actually help our clients make their homes more sustainable (as well as more beautiful and liveable) when renovating. She is also happy to advise us even though our technical grasp of the subject matter is a bit lacking at times..

Cath Hassell of Ech20 - our APM Renewables specialist

A couple of initial thoughts:

  • Define ‘sustainable’ – we’re using this in a wide but fairly unspecific sense of the term to mean making improvements to existing buildings in energy efficiency and carbon footprint, and taking into account the environmental impact of producing/ using and eventually disposing of the various products/ systems available.
  • Costs savings – some renewables products have a fairly clear and definable saving/ financial benefit attached – selling electricity back to the national grid/ producing your own so you don’t have to pay for the Grid to provide it to you.  Others have a much more nebulous financial upside.  We take the view on these that, subject to the cost to supply and install being tolerable (a subjective view), you’re doing so on the assumption you are saving energy and are therefore helping the planet and hopefully in the long run also saving money on the reduced cost of energy you’re using.
Project on site in The Chilterns - Renovation by Absolute Project Management
A grey day but still a lovely shot of the view from where we are on site in The Chilterns, with lots of green – something that we would like to see more of.

Our brief to Cath at a Crouch End renovation project currently underway – how to make the current house, as it is, more sustainable/ energy efficient (while bearing in mind cost v benefit analysis) and how to design/ build the areas that are being changed (a rear extension and a roof extension) with the same criteria in mind.  Her advice, in broad summary:

  • Insulation is key – of existing surfaces – floors, ceilings, roofs, walls (though take into account you may need to improve ventilation at the same time).  Considerations when choosing insulation include:
    • Internal or external – external means no thermal bridges so is a better solution but may be restricted by planning rules.
    • Thickness (choose the best option to fit into the space available) – if fitted internally, bear in mind it will reduce the volume of the room unless it can be fitted in a gap between existing surface layers.
    • Environmental aspects of the production and ultimately disposal of the product used
    • Cost
  • Fit double or triple glazing to replace single glazed windows (another form of insulation)
The mechanical layout showing an Air-source Heat Pump system to be installed on site, at our project in The Chilterns.
  • Look at sustainable energy sources:
    • ground- or air-source heat pumps to provide heat for central heating and hot water
    • photo voltaic roof panels to generate solar electricity for use in the building 
    • if using PVs, a solar immersion controller to capture ‘spare’ electricity produced by the PVs and use it to (partially) heat your HW.
    • If using PVs, consider fitting an electric car charger
    • keep under review the domestic energy options – there’s much talk of phasing out gas but it’s not clear how realistically this will be replaced in the short term
  • For central heating, fit underfloor heating rather than radiators where possible 
  • Waste water Heat Recovery Systems – remove and recycle the heat energy from hot water after use in showers/ baths, etc. – various systems and all subject to space available/ extent of plumbing work needed
  • Energy efficient appliances – older appliances in homes that can often be replaced with significantly more efficient options (cheaper to run, too) are central heating boilers, fridges, TVs, washing machines/ dryers, dishwashers and kettles
This gorgeous photo shows a Solar panels fitted on a residential home, by Vivint Solar, sourced through Unsplash.

We’re quite excited to be working on a project currently on site (outside London, so space is less of an issue) on which Cath is also advising where the clients are having fitted:

  • Air Source Heat Pump (as shown in the detailed diagram above)
  • ASHP powered heating for hot water and to power an underfloor heating and cooling system (gas has been eliminated from the property)
  • External insulated cladding
  • Grey water drainage and recovery for gardening use
  • PVs to power most electricity needs with immersion control system to help water heating. Sunpower PV’s are being considered for projects we are currently planning, with an except from their brochure below giving an outline of the energy savings available:

This summary really just scratches part of the surface of the options available – we’ll be looking at each of the systems we’re using in more detail in further journal posts.

If you need help with renovating sustainably, or would like some assistance in your renovation project in general, contact us now!

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