Wrapping up for winter

I’m frequently asked about what can be done to save energy and keep buildings warm in winter so there seems no better time to share some of my thoughts than when I’m snowed in.

With any property, adding extra insulation in the loft is the most important thing you can do. But do be sure to allow gaps at the eaves so air can circulate in the roof space above the insulation, otherwise moisture can build up and cause rot. It’s also important to make sure that any water pipes in the loft (and elsewhere) are well lagged to avoid them freezing. Wrap the water tank in insulation but don’t insulate underneath so that some of the warmth from the house rises up to keep it from freezing. Don’t forget to insulate the loft hatch before closing it! It’s worth remembering that there’s a range of natural and renewable insulation materials available including sheep’s wool, hemp, cellulose fibre – made from recycled newspaper – and wood fibre.

Having heavy curtains and drawing them at dusk helps to keep heat in and it’s well worth closing internal shutters if you’re lucky enough to have them. Key holes let heat out and draughts in so cover them – there are special ‘escutcheons’ with swing covers that do this. Don’t forget the letter plate. Buy a purpose made draught excluder or hang a heavy and weighted piece of cloth over the opening on the inside of the door. Heavy curtains that can be drawn across external doors also help keep the heat in. Draughts under doors can be kept at bay with homemade fabric ‘sausages’ stuffed with old tights.

Think about the heating system. Make sure the hot water tank is lagged and fit thermostatic radiator valves so they can be adjusted individually; this means that you can have the living room really warm but keep the bedrooms cooler. It not only makes the house much more comfortable but saves on your energy bills.

Windows can leak heat and be draughty. Overhauling original windows is far better than installing replacements which are not only expensive but can ruin the look of an old building and destroy its history. There are now many specialist window companies who do an excellent job of overhauling windows and, at the same time, fit special brush strips that stop the draughts and are inconspicuous. Secondary glazing, which is fitted on the inside of the window, is another option.

Gaps in floorboards and under skirting boards are often a major source of draughts. They can be filled with string of varying thicknesses depending on the size of the gap. Stain the string to the right colour and then push it into the gaps with glue but be careful not to get the glue on the face of the boards.

Dealing with damp will help you stay warmer as damp walls are less thermally efficient that dry ones. But this DOESN’T mean having injected damp proof courses installed which can be damaging to old buildings. Instead, deal with the cause. For example, a leaking water pipe, broken gutter, soil banked up against an external wall or an inappropriate cement render. See Why old buildings need to breathe.


  1. fugitive ink on December 6, 2010 at 9:55 pm

    Thanks for this practical, helpful post. As someone who’s just about to acquire an old house very much in need of insulation, though, is it true that the installation of sheep’s wool insulation doesn’t attract the same cash incentives, via various government schemes, as does mineral wool insulation? If so this seems more than a little mad to me, as we also – I think – pay to subsidise sheep farming. I’d love to use sheep’s wool in our house, not least because it apparently ‘breathes’ better than mineral wool does, but if it both costs more than mineral wool AND doesn’t attract the same financial incentives, I am not sure that I can afford it!

  2. Mark Lynn on December 8, 2010 at 9:09 am

    Good quality sheep’s wool insulation such as Thermafleece is a better insulator than low density fibreglass insulation so you need less of the wool compared to low density fibreglass (about 13% less). It also lasts longer. Thermafleece is approved by the British Board of Agrement for the life of the building so you don’t have to worry about replacement costs which have a big impact on the ‘whole life’ cost.

    In terms of subsidies, Thermafleece is eligible for CERT funding; the difficulty is finding a CERT registered installer that is willing to install Thermafleece. It is worth speaking with the installer and asking if they will install Thermafleece. It is easy for us to get the insulation to them. The CERT subsidy will make the insulation cheaper and narrow the price gap. You will still pay more for Thermafleece but it is a better performing premium product at the end of the day.

  3. fugitive ink on December 8, 2010 at 11:07 am

    Many thanks for that very informative and helpful reply, Mark – we will definitely pursue the Thermafleece option to see whether it will work for us.

  4. Voltage Optimisation on December 10, 2010 at 6:33 am

    Thanks Mark and Roger for the useful tips.