Renovation of a mid 19th c Cotswolds cottage

[KLD]

Time to owe up then:  Sadly nor many pictures (there must be some, I'll go and hunt them down, eventually.)
We moved into a cottage in North Oxfordshire in 2003, first renting it for two years, before we were able to buy it. Buying a house without having to move house, 
It's main part probably dates from the mid 19th century, has half meter solid(-ish) stone walls, but was extended twice, adding to it at either end. One addition most likely was built as a workshop or similar, and was only incorporated into the house in the 1950s. The other is of early 1970s vintage.

So, in at the deep end, here is a list of things we've done to it.

40-year-old extension:

partly new roof, insulation between and under rafters (140mm Kingspan)
new timber suspended floor above unheated garage, insulation between joists, chipboard structural layer, UFH in 40mm screed, tiles over
internal insulation to walls, 50mm Kingspan between timbers, foil backed PB over
new DG windows, tilt'n'turn

9 inch solid brick wall extension:

demolished, all bricks cleaned and re-used
new build extension in Thermalite, part-filed cavity, old bricks for outer skin
roof insulation 150mm sheep wool between rafters, 60mm woodfibre board across on the outside
100mm Kingspan under screeded floor, UFH
new DG windows + door (Bereco)

1850th cottage:

"solid" rubble walls, 500mm wide, no insulation
one and a half stories, rafters only 4 inches, rockwool insulation only in crawl space (50% of roof?)
two new DG windows at rear, front windows SG sash (completely refurbished, draft brushes fitted)
front door doubled up with 50mm Kingspan), draft stripping all round
both open fireplaces converted to WBS, chimneys lined in flexible stainless steel
kitchen floor excavated, new concrete -- insulation -- screed w/ UFH fitted

heating system:

mains gas, condensing boiler (Viessmann Vitodens 200W), separate weather compensation for radiator and UFH circuits
40x 47mm ET Navitron panels, 210L thermal store
bathroom with shower only (no bath)


Now the good news: quite apart from the fantastic increase in comfort here are a few figures for the
gas consumption (in kWh) during the heating period (mid October to early May):

2003-04    22969
2004-05    19525
2005-06    20441
2006-07    14091
2007-08    13427
2008-09     (wai-i-i-i-ti-i-ng for the new boiler, brrrr)
2009-10    8295


Luckily I have no precise idea about how much we spend   
But I'm not a big fan of the purely financial perspective. We've created a house that truly feels like a home, it was (erm, still is, or have you ever seen a diy project really finished?) great fun doing it all. Would I do it again? Yes, but with quite a few changes in the details.

Klaus

[Mudman]

Well done, very interesting.
yes, would love to see any photos you can dig out- everyone else will say that too as you know!

If i understand properly, there's not a lot of space in the cottage's attic for insulation- have you, even so, got enough would you say, or have you thought of doing something different with the loft insulation- considering how little space you have, you could try kingspan between joists instead of the standard rockwool, and then more (thinner) kingspan across the top of the joists? just thinking it has about twice the insulation value than rockwool so with limited depth available, you'd be better off...

[KLD]

Mudman

Those two rooms upstairs are our bedrooms, which we don't heat anyway. I've shied away from doing anything to that roof section, fearing that we'd need to replace the whole lot. The gains would probably not be huge, so I've pushed that whole issue into the long grass 

Klaus

[Amy]

Klaus, your gas useage reduction figures speak for them selves. What better incentive?

[desperate]

Power to your elbow Klaus, I know north oxford quite well, Mrs Desp grew up there and my outlaws still lurk there-ish

I am sure you have done it proud.

Seeya

Desp

[SimonHa]

Would I do it again? Yes, but with quite a few changes in the details.

Inspirational! 

Just out of curiosity though, as someone on a similar path to you albeit several years behind, what sort of things would you have done differently?

Simon

[KLD]

Simon

Most of those changes would be specific to this project. One major issue is the wall construction in the new extension. Now we have (from outside in): reclaimed bricks, 50mm open cavity, 75mm celotex cavity boards, held between wall ties, 100mm light weight concrete blocks, plasterboard dab-'n'-dot-ed. Fitting the celotex boards was an awful pain, and I don't think it is possible to fit them without any air gap to the concrete blocks. This very much limits their usefulnes (air circulates between insulation and blockwork). Same on the inside: air can move between PB and blockwork. Sound travels freely in that gap, too.

Klaus

[StBarnabas]

Klaus
a few more pics please? I have posted many of StBC and many more to come with the new thermal store and wind Turbine install
Sean

[KLD]

With Ivan's prompt to "Go and Play Outside (take your camera for a Poor Man's Thermal Image)" in mind, I stole KlD-chen's new point-and-shoot and waited patiently for the snow to melt a little, to reveal just how bad the old part of the cottage is.
Pic1 clearly shows why solar thermal doesn't seem to do much nowadays  . More to the point, the old outside wall (50cm rubble stone) -- in line with the near chimney -- directly supports the tiling battens, meaning there is no insulation between it and the slates. The upstairs room in the new extension is heated, and has a vaulted ceiling. Shall we call that a cold-bridge ?  Note how there are very few icicles off the new roof compared to the old.
The 40-tube panel are kept from freezing by recirculation. The inlet is into the right hand side, where the sensor reads between 7 and 20°C, while the outlet only climbs to 5 or 6°C with a minimum at 2°C. Despite the fact that both pipes are insulated to the same standard, you see how the rhs panel connection is now exposed.

Pic 2 shows the old roof. The ceiling inside is about half way up the slope, so the attic is tiny. The are two vents to let out a little more heat. The far chimney is the one with the woodburner on, but the stack doesn't seem to be much warmer than the unused one. Well, it's lined and backfilled with micafill.

Pic 3 Our lodgers, the Sparrow family, wanted to have their own set of icicles, too.

Pic 4 is the summer view.

Klaus

[KLD]

pic 3 + 4

[dhaslam]

Doesn't the sun take the snow  off the  solar panels and the  southern side of the roof?   

[SimonHa]

...
Pic 3 Our lodgers, the Sparrow family, wanted to have their own set of icicles, too.
...

Haven't they installed Kingspan then

[KLD]

No, the Sparrows are rather too green for Kingspan, they use hey (for their floor insulation at least)

[KLD]

Doesn't the sun take the snow  off the  solar panels and the  southern side of the roof?   

It dumped about 40cm in one go last Saturday. Once that is down, the panel doesn't seem to get any warmer than the rest of the roof.
K.

[davec]

... Fitting the celotex boards was an awful pain, and I don't think it is possible to fit them without any air gap to the concrete blocks. This very much limits their usefulnes (air circulates between insulation and blockwork). Same on the inside: air can move between PB and blockwork. Sound travels freely in that gap, too.

Klaus

Klaus, I'm interested in what you say here... we're looking at externally insulating a stone farmhouse and it's fairly certain there'll have to be a 50mm air gap between the old walls and the insulation to allow the original shell to breathe. Do you find sound travel is a particular problem? We're thinking of moving windows to the outer shell so should we be thinking of ways to reduce 'whispering gallery' effects? If so, any suggestions?

Many thanks, DaveC