Personal story:

My partner and I have been involved in social and environmental issue for many years and I work in the field of energy conservation in buildings. We enjoy living in the centre of London and walking to events in the areas around but also travel a lot. Having a flat that is warm and comfortable, easy to heat and does not cool down when left, is a great benefit.

Motivations:

Before we moved back into this flat, which had been rented out while we lived in Brussels,it seemed opportune to carry out a sustainable refurbishment to warm up the flat and reduce the energy consumption. The flat had the original sash windows and one Crittal metal framed window, solid brick walls and an uninsulated roof being on the top floor. Heating was from an old floor mounted gas boiler with storage cylinder. It was pretty cold in winter and hot in summer.

For more, see my article on our refurbishment: Is flat and apartment eco-renovation easier?

Property background:

One of the reasons we bought the flat was that it has a wonderful direct view of St Pancras station over Camden Town Hall. Being on the seventh, top floor it is lovely and light, views all around- but when we bought it, very cold in winter! Solid brick walls, single glazing, no roof insulation, like many flats. Solution -insulation all round and now its toasty all the time with minimal heating.

Key changes made:

Insulation of the external walls and the roof, and a mixture of double and secondary glazing, is what has transformed the flat. Several associated improvements, such as a combi boiler, small radiators and ceiling mouldings have transformed a cold basic flat in a beautiful luxurious central London pad.

Measures installed in detail:

• 3 windows with secondary glazing.
• 2 new sash windows with argon filled double glazing
• Internal wall insulation 70mm PIR and plasterboard. U value 0.24.
• Internal ceiling insulation 30mm PIR between battens and 35mm phenolic foam and plasterboard. U value 0.25.
• Whole house draught stripped.
• Condensing boiler, TRVs, Programmer and thermostat.
• Low energy lighting.
• Extract fans in kitchen and bathroom

Benefits of work carried out:

Cracks in the walls and ceiling have been covered by the insulation, double and secondary glazing has taken away cold areas so that the radiators have been moved to the central area of the flat avoiding unsightly pipe runs round the rooms. The double glazing has reduced noise from the surroundings making the flat very quiet. The replacement of the old floor mounted boiler by a wall hung combination boiler has made a lot more space available in the kitchan and for storage. The flat is now always warm, cools down very slowly and requires little heat from the boiler.

Favourite feature:

We lived in a wonderful top floor (rented) flat in the centre of Brussels for several years but it was always cold in winter, despite the central heating, due to solid walls, uninsulated roof and a lot of draughty single glazing. Coming back to London and always being comfortably warm in this flat, is something we appreciate every day!

Project update:

Our flat is in a block of 200 flats and our refurbishment has developed interest from others in the block. We hope to spread the word and get our energy measures replicated in other flats.
We have recently replaced the living room window with a wooden double glazed unit, it was steel framed with secondary glazing.

Updated on 23/05/2012

Common questions and answers for this SuperHome

Did you take on an architect or consultant and did you use a general 'green' builder for all work or did you find individual trade specialists?+

We have not used an architect on these works and had one builder to do the insulation, mouldings, kitchen double glazed window and some plumbing changes.  I used a different contractor (previously) to do the new boiler and secondary glazing was done in two stages by Everest.  The final work we had done was a new shower room by another company.  So a lot of different stages and contractors because of different pressures and our own movements.  I feel that to use just one builder/contractor might have been better and cheaper.

I am an energy consultant and have quite a lot of practical knowledge about buildings and energy and so knew what I wanted and did not need another advisor.  There was no remodelling of the (small) flat.  For the wall and ceiling insulation I did use a contractor who had done this sort of work before and we did work out together exactly how he would do it and the systems to use, and that worked well. This was Ray and Tony of Unwin and Sons, 61 Brook Road, Essex and I have no complaints about them at all.  They did a good job with no problems showing after 2 1/2 years, just what I asked for, with excellent subcontracting to a company doing the new ceiling mouldings. Very competent all round.

If you wish to consider balancing between different options (insulation types, thicknesses, positions and glazing systems etc.) I suggest you use a competent consultant like Parity Projects, who I know and they are excellent.

How did you feel about the reduced space due to internal wall insulation? Did you have to redo any electric work due to it?+

We certainly don’t notice the loss of internal space, and with the repositioned radiators and loss of water storage tanks and removing of one fitted cupboard, I guess this makes up for it.  We have also changed some of our furniture for smaller stuff but we moved from a larger flat in Brussels. Some electric sockets were moved to the new walls, no problem.

How did you deal with the possibility of interstitial condensation with internal wall insulation?+

Some people think breathable insulation is best but I prefer installing a good vapour barrier with internal insulation to stop the moisture tracking across to the original wall in the first place.  Condensation is a much discussed and not necessarily understood subject.  But we know of no interstitial condensation problems if internal insulation work is properly carried out and in some instances measurement of damp in timber beam ends with internal insulation installed, show reduced moisture content over time. Research and monitoring is ongoing.  I think wall dampness is often associated with rising damp and penetration from outside, and often this is kept in balance by subsequent drying off to the outside.

Have your energy bills shown any tangible savings?+

We don’t live a very consistent life and the flat was rented out before we moved back, so there is no direct comparison.  Our average annual gas consumption over the past 2 years is under 3000kWh, i.e. not much (includes cooking).  As the flat always feels so warm, cools down slowly and heats up quickly I am sure the energy improvements are working very well.  The new comfort level is wonderful! The double and secondary glazing also makes the flat much quieter and we are close to busy roads.

Have you considered going near passive for your flat? Is it actually even possible for a flat to be passive given that we have no place for solar panels and air exchange machine?+

Rather than “passive” are you thinking of “zero energy”?  We have passive ventilation and some solar gain in our flat, and there is a lot of thermal mass internally with the brick internal walls (all normally seen as passive features).  As to zero carbon dwellings (like PassivHaus standards plus) using very high insulation levels, mechanical ventilation with heat recovery, and solar thermal and PV, they can be expensive, although a very satisfying concept.  I believe that it is more important to treat all you can to a very good level (e.g. high insulation, double glazing with low e and argon fill, condensing boiler with top controls, draught proofing, low energy lights and appliances) and not necessarily go for broke!  New housing may be a bit different as it is generally cheaper than refurbishment to go all the way.

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