Sustainable Homes website

[Yellow Fang]

We've also had a bit of a scandal here of late, unreliable or unqualified installers cocking up the installs etc. It's all added a bit of a nasty taste to PV.

You can't qualify for FIT in the UK unless your panels are installed by an accredited installer. However there seem to be a lot of people getting into the industry, so it's possible they won't have that much experience, even if they are accredited.

 

[CopperBrompton]

And the cost of building a spacious, open-plan 5-bedroom negative-energy house? approx. £170K!!

Remember, though, that the typical build-cost of any house is roughly the same as the cost of the land on which it is built, so a realistic all-in price would be more like £340k.

 

[Archie_tect]

Depends on the location Ben, and the type of land... so many variables. One thing to remember, if it looks too cheap to be true, then there will be something that they aren't telling you.... buyer beware!

If a flat, square infill piece of land is offered below sensible price it may have all sorts of problems- high water table/ drainage/service easements/ restrictive covevenants/ mining issues/ fill.... always check it out properly.

Meanwhile back to sustainability and renewable energy....

Yes, to get FIT you have to use an accredited installer but that makes sense, you wouldn't want Joe Bloggs Half price PV Systems [2010] Ltd installing your system without checking them out.

Depending on where you are summerdays, there are some very good firms out there.

 

[annedonnelly]

Well, my favourite installer (he's already installed solar hot water and a heat pump for me) has calculated a payback time of about 12 years. He's going to measure up properly in the next week or so.

As you say if the money is sitting in the bank earning minimal interest it makes sense to make this sort of investment. Unless it's going to need massive disruption to the house I'll almost certainly be going ahead with it.

 

[Ghost Donkey]

The solar heating vacuum tubes are of particular interest to us. We have a south facing roof which gets a lot of winter sun. We have an old style boiler with a water tank. The tank would need replacing but the physical space and plumbing (excluding for a roof panel)is there. We mainly use hot water in the evenings. The only downside is we will be looking to move house in around 4 years. If it adds to the value of the property then great. Paying a couple of grand off the mortgage may be more financially viable due to the saved interest payments. We're looking at it as we are thinking of replacing the boiler next year so it would be a good time to do it. Another house on our street has one of these set ups so we know the roof should be able to take it.

 

[Archie_tect]

The solar heating vacuum tubes are of particular interest to us. We have a south facing roof which gets a lot of winter sun. We have an old style boiler with a water tank. The tank would need replacing but the physical space and plumbing (excluding for a roof panel)is there. We mainly use hot water in the evenings. The only downside is we will be looking to move house in around 4 years. If it adds to the value of the property then great. Paying a couple of grand off the mortgage may be more financially viable due to the saved interest payments. We're looking at it as we are thinking of replacing the boiler next year so it would be a good time to do it. Another house on our street has one of these set ups so we know the roof should be able to take it.

Ghost Donkey, check the roof pitch and orientation as evacuated tubes are more expensive than flat plate collectors and are only marginally more efficient on direct south facing 30 degree slopes. Where evacuated tubes gain, in efficiency, is where you can angle them to face due south when installed vertically on a SE or SW facing slope or when you face due south but have a low or a steep pitch when you can install thetubes horizontally and angle them to take advantage of high summer sun or low winter sun [but check for overshadowing.

You can always replace your old hot water tank with a double coil tank for your solar heating pipes and keep your old boiler for a while. If moving in 4 years you should get your investment pay back in 24 months, depending on how much you spend and what your hot water useage would be, and whether you adjust your lifestyle to use the hot water in the evenings. You will get the benefit even keeping your old boiler in place but the house should have a higher value with solar heating as the EPC rating will be higher and you can demonstrate to prospective buyers what an improvement it is so market your house to suit. It should sell better as your house will stand out from the rest..

Before installing solar heating though install a total of 400mm insulation to your loft space now as that will give the greatest return for your money. BUT make sure you maintain the cross ventilation within the roof void or you may get condensation on roof timbers.

 

[Yellow Fang]

Well, my favourite installer (he's already installed solar hot water and a heat pump for me) has calculated a payback time of about 12 years. He's going to measure up properly in the next week or so.

As you say if the money is sitting in the bank earning minimal interest it makes sense to make this sort of investment. Unless it's going to need massive disruption to the house I'll almost certainly be going ahead with it.

Good on yer! What sort of heat pump did you get? I hope you don't get stiffed over the Renewable Heat Incentive like early adopters of the Feed in Tariff were for electricity.

 

[Archie_tect]

Anne, who did you use? Did you go for a ground source or air source heat pump?

[Edit: Great minds Yellow Fang!]

 

[CopperBrompton]

If a flat, square infill piece of land is offered below sensible price it may have all sorts of problems- high water table/ drainage/service easements/ restrictive covevenants/ mining issues/ fill.... always check it out properly.

There's a fantastic restrictive covenant on all the properties in my road: nobody is allowed to park a caravan outside any of them. :-)

 

[annedonnelly]

Anne, who did you use? Did you go for a ground source or air source heat pump?

[Edit: Great minds Yellow Fang!]

It's an air source pump. On the side of the house above the garage - we were a bit worried that the noise might be a bit echo-y between the two houses but it's not been a problem. Only regret is that I didn't get the pump at the same time as the solar hot water.

The pump is manufactured by Daikin, although the installer also likes the Mitsubishi ones. Installer is Northburn Solar and I'd highly recommend them.

Fingers crossed for the RHI - it's been delayed but not scrapped in the spending review.

 

[Archie_tect]

Did you have a mains gas boiler before? I'm curious to see how the ASHP compares with mains gas use as we've looked at ASHPs before mainly down to the 1:3.5 electric units in/energy out ratio. Could you let me know how it performs through the winter?- have you got an external temperature sensor?

 

[summerdays]

Never even heard of an Air Source Heat Pump before ... and being thick when it comes to physics not quite sure what it is having read wiki on it either? Something like the back of a fridge...?

 

[Archie_tect]

Never even heard of an Air Source Heat Pump before ... and being thick when it comes to physics not quite sure what it is having read wiki on it either? Something like the back of a fridge...?

Summerdays,


It's the equivalent of a fridge working 'backwards' recovering heat from external air and releasing it into the house. It relies on the temperature difference using the latent heat absorbed from the external air.

It means that one unit of electricity 'generates' between 3 and 3.5 units of heat, and running costs are roughly equivalent to the cost of using mains gas for a similar heat output.

 

[annedonnelly]

Did you have a mains gas boiler before? I'm curious to see how the ASHP compares with mains gas use as we've looked at ASHPs before mainly down to the 1:3.5 electric units in/energy out ratio. Could you let me know how it performs through the winter?- have you got an external temperature sensor?

Yes, an elderly and probably very inefficient gas boiler. I've also replaced the radiators with more efficient ones so I expect that to have a difference too.

I assume there's an external sensor as there's an option for "weather compensation".

Very happy to report back during the winter - PM me a reminder any time you like. Actually I've also got the manuals and specs on a CD so you can see those if they're of interest.

 

[Archie_tect]

Yes, an elderly and probably very inefficient gas boiler. I've also replaced the radiators with more efficient ones so I expect that to have a difference too.

I assume there's an external sensor as there's an option for "weather compensation".

Very happy to report back during the winter - PM me a reminder any time you like. Actually I've also got the manuals and specs on a CD so you can see those if they're of interest.

Definitely take up the external compensator option as it assesses the external temperature and cuts in to suit or closes down to protect itself in extermely low temperatures temporarily when/if the unit has to 'defrost' itself.

Using radiators let your installer know the sizes as he will need to size the ASHP to suit.... I'll shut-up, he'll already have done that!