Out of interest, what's the sqm of the property and which manufacturer and what size pump did you go with?
As I've just said in my previous post, it makes such a massive difference when a whole house view is taken; insulation + free heating + free electricity = perfection!
Originally the property was a hipped roof bungalow built by SWMBO's grandad in 1937. Apparently he bought the land & built it for £700. He was offered land for another 7 (I believe) houses for a total of £200 but couldn't afford it at the time! The bungalow he built was 72 sq.m.
When he died he left it to mother in law, in trust for the 3 grandchildren. As not much had been done to it since he built it, it was in poor condition. The family were able to have the will modified to allow mother in law to sell the bungalow & split the proceeds then. We didn't really want it as we were happy where we were. SWMBO's 2 brothers were then "fighting" for it before they both dropped out, one to keep the peace then the other realised that he couldn't afford to do it up.
Mother in law asked me to take it on to do up & sell but I could see that I would end up doing all the work and having to share the profits with the 2 brothers. Tried to convince mother & father in law that using the equity in their own bungalow we could do it up for mother & father in law to move in. Father in law refused to move as "he had his garden just how he wanted it" (couldn't accept that he could have a new garden just how he wanted it!) and "didn't want to move away from his neighbours" (this place is all of about 250m away!)
So SWMBO & I bought it off the family to do up & move in ourselves.
Planners were decidedly awkward so we were restricted at the time as to what we could add. I did get a basement included in the approval but never went ahead with the construction of that.
We took the roof off and took down the entire rear wall. Took out all the floors to allow for new concrete, insulation & liquid screed. Remodelled the rear rooms and insulated the remaining external walls. We added a rear extension - 42 sq.m with vaulted ceilings and we put a new roof on with rooms in the roof - 57 sq.m
So a total of 171 sq.m, insulated in excess of the Building Regulations which were in place in 2011/2012. I doubt that we meet or exceed current standards though.
Heating system was designed by Nu-Heat and at the time they were pushing Hitachi ASHP's It is a 7kw with a 100 litre buffer tank. Buffer tank has a 3kw immersion heater in it in case the ASHP can't cope in extremely cold weather. I'm not aware if the immersion heater has been used yet as the operation is all controlled by the brains of the system.
The system designed by Nu-Heat was over engineered. On the 1st day of operation it was switched on to achieve16 degrees C and we were intending to increase the temperature gradually to dry the property out. When I returned the next morning the temperature in the house was 27 degrees C!
A engineer was dispatched to alter settings in the brain. It had apparently been set up for a "new build" property, not taking into account the levels of insulation we had installed.
Nu-Heat advised to have the heating on 24/7 and let the "brains" control the heating. Hot water was on a timer. But after a period of inadequate temperature water they advised us to let that run 24/7 also.
So we have more hot water than we need and the temperature in the hall is currently 23 degrees C with an outside temperature of 0 degrees C.
Nu-Heat no longer supply Hitachi ASHP's, now preferring NIBE. I wouldn't have another Hitachi out of choice as it is quite a noisy unit.
