Introducing energy and water saving measures during a renovation project

[Sinkingfeeling]

We're due to move to a new house shortly which will need fairly substantial renovation and are keen to introduce some energy and water saving measures as part of the work, which is likely to take us a few years to complete. Which measures do you think provide the best return on investment do you think? Double-glazing? High-spec roof/wall/floor insulation (we have no cavity walls)? Efficient boiler? Rainwater recyling system? I can't find any recent threads about this.

Apart from the loft and pipes, most of the work has a poor return.

Insulate the loft to 250mm depth, and the hot pipes, and cure draughts. Add extractors in bathroom and kitchen or you will get condensation, which will be especially bad if anyone has a shower or drapes wet washing around the house.

if you need new windows anyway, you may as well have DG. If not, the cost will outweigh the energy saving for the rest of your life.

If you are having new floors, yes, insulate them. If you can get at the underside of wooden floors yourself without paying someone, yes (and remove the rubble and clean the airbricks while you are down there)

If the walls need plastering, you may as well have them internally insulated using Kingspan plasterboard.

External insulation of solid walls is expensive, but you might consider it if they need re-rendering or re-cladding.

I'm planning to put in a grey water harvesting system. I don't know about return on investment but they seem like a very good idea to me.

PigletJohn, thank you - that is tremendously helpful. We did wonder about insulating the walls internally as they'll be hacked about anyway because the damp-proof course needs to be renewed and the house needs to be rewired.

Rhubarbgarden - is it a water harvesting system with an underground tank you're considering? We're interested in these too - can't see how using rainwater for the washing machine and to flush the loo can possibly be a bad thing, but suspect they're expensive to install. We'll be on a water meter in the new house.

we took ALL water out of the loft - switched to a mains pressure system - which means mixer taps work well
and put in a solar thermal panel that does our hot water (all of it in summer, half of it in winter)
uber efficient Vaillant boiler
accurate timer clock
INSULATE, INSULATE, INSULATE - we did not put enough celotex in - retrofitted an extra six inches.
the best TRVs you can get and make sure that any central heating pipes made out of metal are sleeve insulated
sound insulation into all stud walls (the bit we regret not doing)

we have a big garden so set up 500 gallon water storage tank that takes from the whole of the roof - had wanted to sink it underground but costs got too much
deffo double glazing (with trickle vents in all main openers)

interestingly we had to have extractors put in the bathrooms and utility room and have NEVER used them

oh yes that reminds me - put in a new water supply pipe right out to the mains under the pavement - 25mm, but 32mm is better. It will give you plenty of flow, which you will appreciate if you have a powerful combi; still more if you have a Megaflow.

It will supply enough water that you do not have to experience a drop in flow at one tap, if someone turns on another (provided the internal pipes are also a fair size).

And if you are in a hard-water area I would add a water softener (ion exchange type).

I looked at rainwater harvesting tanks for our back garden but as we're not on a meter it would cost a lot and save next to nothing. We aren't big gardeners so even being able to water the garden during hosepipe bans doesn't help.
But as you say, I can't see how washing clothes and flushing the loo in rainwater could be a bad thing

I also looked at solar water heating and/or ground heat exchange pumps, but was told by the company who installed our PV panels that as we have mains gas it would take forever to pay for itself. Was very happy with them for not just selling them to us anyway

This is a good place to start:
www.energysavingtrust.org.uk/Publications2/Housing-professionals/Refurbishment/Sustainable-Refurbishment-2010-edition

I also used this site to help work out which were the most cost effective measures - ie what combination could get me highest up the EPC ratings for a reasonable/minimal spend:
www.eonenergy.com/At-Home/Products/EnergyFit/
It is not quite as flexible as it once was, but it still gives you a good idea of what you need to do by filling in the survey and then getting its recommendations.

We did more than we expected to, but it really has made the house a lot more comfortable than it was originally. We:

• draught stripped all our doors, letterbox, sash windows.; replaced single glazed casements with double glazed and secondary glazed the bay window in our sitting room.
• we insulated our roof room ceilings with 50mm celotex and replastered (replacing only 100mm of rockwool which was useless).
• we replaced the boiler with a condensing combi (Vaillant Eco-tec) including a built in time clock, TRVs on new radiators and one central thermostat.
• we insulated the small amount of walls below the roofline and drylined the bathroom walls.
• we insulated the hot water supply pipes and also radiator pipework where it passed in unheated semi-external voids (roof and under floor voids).
• We changed all our bulbs to compact fluorescents.
• I made long thick curtains with lovely thermal linings to cut down on drafts.

I wish that we could have done the following (if we had been staying long enough to make it worthwhile):

• Made the heating work on a 2 zone thermostat system and added TRVs to all radiators but it was too much to alter the existing system.
• Had a hot water tank capable of accepting solar water heating
• Installed a water divertor to send bathwater to a garden irrigation system.
• Installed heat exchanger extract fans to save heat loss from bathroom and kitchen extracts while still getting rid of moist air.
• insulated between the ground floor joists and sealed up all the gaps around the floor edges to stop draughts.

If we are lucky to move to the sort of period property I would like, I would also consider refurbishing existing shutters (maybe to include insulation) and using them at night to keep heat in. Alternatively SPAB have been trialling glazed hardwood internal shutters which create a sort of triple glazing system or double glazed secondary glazing thing. Could look really nice and keep things very cosy.

I would be careful about drylining rooms with insulation. It is tricky in an old house and I worry about what we have done. Interstitial condensation can build up and it might cause dry rot etc. So proceed with caution!

Also be careful with new double glazing. The life of the units is not terribly long and maintenance/recycling impossible. My original 1910 windows can be filled and painted and repaired with a bit of work every 5 years to keep them going. It is a hassle but doesn't cost that much compared with replacement glazing which only has a 15-20 year lifespan. It is worth thinking about if you have windows that could be saved and you are up for a bit of painting. It also makes the house look nicer IMO.

If you live in a pre-1910/1920 house consider calling the SPAB technical help line as they have some really good technical advice on improving energy efficiency without destroying the character of your home. Old houses also need "breathable" construction as they are not built with the same "seal it up" philosophy of new homes and you can inadvertently cause damage if you start mixing up the two systems.

Lastly (good luck if you got this far!) although meters are not mandatory now, I can see a time when they will be. All of East London had meters installed 2 years ago when the mains were replaced. I reckon once the whole of Thames Water's area is metered, they will withdraw the fixed tariff. We didn't look into water saving stuff much when we did our place but next time I would maybe look into the water saving sanitaryware and taps, as well as water re-use systems. It all looks a hell of a lot better (and doesn't cost as much) as it did 5-10 years ago!

Good luck

Oh yes - lightbulbs!
We put in CFL fittings in some places and bulbs in all other places.
However I think that like the old bulbs, CFL are due to be withdrawn in about 2016? So do investigate this and maybe consider going for LEDs. Again the prices are really coming down now and technology has really come on to such an extent that theatres are even using them - and I never thought I would see that!

East access isolation switches to your major appliances cost very little if you're rewiring and can save a lot in standby costs if you remember to turn them off.

If you're using radiators individual thermostatic valves on each radiator mean you can keep different parts of the house at different temperatures. Bedrooms cooler, unused rooms low or off etc.

We had a local carpenter do our windows for us - It was significantly less than upvc double glazing at which I'm still shocked. we did paint them ourselves, they were supplied primed though. We kept the majority of the hard wood frames which we scraped back, filled and painted, the carpenter then made in keeping 6 section cottage windows to replace what we had. The glass is double glazed but the beading is placed ( fixed over the glass on both sides with trim pieces between the glass sheets) rather than having 6 individual double glazed panes per window section.