Introduction

[Confused123]

Good morning,

I live in a 1930s converted bungalow and am constantly trying to answer the question 'what work can I do myself and when should I seek help?' I hope to pick up some guidance here.

Gary

[markc]

Good morning and welcome, what are you good at? And what do you do already?

anyone can put paint on … except me, I hate it. Laying a patio is pretty straight forward. Electrics, plumbing and structures need to be left to the pro’s.

but, if you are reasonably fit then you can act as a labourer and save some money that way

[SteamyTea]

Welcome

 

Get to grips with the insulation and airtightness.  Stop those draughts (or is it is drafts). Read up on here about ventilation.

Find out how your current heating system works.  There could be energy savings to be made there (putting my old mates heating into ECO mode helped a lot).

 

The rest is DIY.  First room I did cost me about a £1000 to do back in the 1980s, had to buy loads of tools.  After that it got cheaper.  I even managed to renovate my back door last week,  Got the twist out and it now closes against the frame, 3 quid draught excluder keeps the wind out.

[joe90]

Good morning Gary and welcome, yes we need to know what your capable of but saying that there are lots of things you can do with a little guidance from the collective here, remember, there is no such thing as a stupid question, stupid is not asking and we have all been there in the past. Insulation and airtightness is the key.

[Radian]

19 minutes ago, SteamyTea said:

Get to grips with the insulation and airtightness

 

7 minutes ago, joe90 said:

 Insulation and airtightness is the key.

 

Insulation is often retrofitable. Airtightness, not so much.

 

My understanding here, which may be wrong, is that when we're talking about airtightness we're not really talking about drafts which are relatively easy to prevent. But of all the things that sap energy (that's costly to replace) air change is thankfully the least in significance due to it's relatively low specific heat capacity. Heating a given volume of air by a given amount requires a lot less energy than the equivalent amount of some other medium such as masonry. I said "thankfully" above because, in my opinion, airtightness is probably the most difficult thing to achieve and can only really be achieved during a new build or complete renovation. And even then, it's not something you can employ a non-specialist to do for you so often becomes the preserve of the fully hands-on self builder.

 

So is it worth chasing airtightness beyond the easily accessible stuff like gaps around doors, windows and wall junctions?

[SteamyTea]

36 minutes ago, Radian said:

So is it worth chasing airtightness

If the volume of air in a building has a mass of 1 tonne, is changed 5 times an hour (typical ACH for a new build) and the temperature difference is 12K. Then that is 150 kWh a year.

Don't sound much, but old houses leak at a greater rate and the delta T is for my house in mild Cornwall.

My small house has a volume of 160 m³, so a mass of 200 kg.  So 30 kWh/year. 6 quids worth of E7 electrons.

Still going to improve it though.

[SimonD]

2 hours ago, Radian said:

 

 

Insulation is often retrofitable. Airtightness, not so much.

 

My understanding here, which may be wrong, is that when we're talking about airtightness we're not really talking about drafts which are relatively easy to prevent. But of all the things that sap energy (that's costly to replace) air change is thankfully the least in significance due to it's relatively low specific heat capacity. Heating a given volume of air by a given amount requires a lot less energy than the equivalent amount of some other medium such as masonry. I said "thankfully" above because, in my opinion, airtightness is probably the most difficult thing to achieve and can only really be achieved during a new build or complete renovation. And even then, it's not something you can employ a non-specialist to do for you so often becomes the preserve of the fully hands-on self builder.

 

So is it worth chasing airtightness beyond the easily accessible stuff like gaps around doors, windows and wall junctions?

 

Good question. It retrofit circles airtightness is claimed to be the first low cost biggest bang for buck improvement followed by insulation. On new build, BRE suggests airtightness accounts for about 10% heat loss. I've seen other figures suggesting 15-20%. Energy Saving trust puts a figure of 30% losses down to thermal bridging.

 

However, countries like Sweden put airthightness at the top of the list in terms of importance for energy efficiency - it's first design for airtightness then insulate. I don't think the overall heat loss is 'just' down to the heat capacity of the air but how that movement of air impacts thermal loss of all elements - we know how much eliminating convective currents within insulation layers improves energy efficiency for example.

 

Like with everything, it's got to be a balance of what is done to what extent and for what cost?