ProDave

One of the small air to air units that do heating and cooling would do, you can get them with one outdoor unit and 1, 2 or 3 indoor units so can do up to 3 rooms. The grey area is the pipework is refrigerant gas, they come pre gassed but you really should get an F gas engineer to make the connections and leak test etc before opening the valves. The beauty of small air to water heat pumps is the refrigerant gas is all pre plumbed within the unit so only water plumbing and wiring to do.

Not heard this. When was your building warrant issued, i.e. what version of regs are you working to?

Who told you that? What is your present supply rated at and why do you think you need more?

It's a warm roof, so insulation above rafters, then breathable felt, then counter battens and battens. All the vents are ventilating is the gap between the tiles and the membrane. If the plastic went above the vent then the membrane would also have to go above it and the vent would be venting nothing.

No problem DIY installing an ASHP. I have more concern how you will power it if completely off grid? They will expect a 230V ac 50Hz supply and even a small 5kW ASHP will need perhaps up to 3kW of ac power. If it is just a small cabin (one room?) then one of the smaller air to air heat / cool units might be easier and you can get those in lower power ratings. Tell us more about your supply? on grid / off grid etc.

Yes. In my particular case on top of the facia board was a strip of (I think it was called) Easy Verge or similar, a plastic strip to divert any run off from the felt down into the gutter rather than just drip down the front of the fascia. Using the one you linked with the vents pointing downwards would have just about blocked them in my plastic strip. But if it works in your case no reason not to use them. Here is an example of one of my eaves showing the straight through vent works but the bottom outlet one would not.

Yes, but I would use this type of vent https://www.roofingmegastore.co.uk/corovent-1m-low-profile-overfascia-vent-with-10mm-air-gap.html

But you go have to notify the land owner that you have submitted a planing application on his land. We did this prior to buying our plot, we applied for outline planning while the plot was still owned by the vendor and only proceeded with the purchase when that was granted.

I would go back to first principles and have a re think. By FAR the easiest extension would be to just extend the main gable ended part of the house at the back. Can you work out a way to get the extra accommodation you want by doing that? If not post a sketch of the existing upstairs and downstairs floor plan and a description of what you want to achieve?

Those air to air units are pre gassed with the refrigerant gas, and rely on you being competent to make a gas tight connection on the pipes when you install them. If not all your refrigerant gas will leak out. It is a grey area whether is is even legal for a non F Gas registered person to install these.

Simple point. Building a new wall costs pretty much a fixed cost per linear metre of wall. So the more area you enclose per linear metre of wall, the lower the cost per square metre of extension. The right hand bit, where the new wall is, is very close to the existing wall (no scale on drawing though) So the wall costs as much but the cost per square metre of that small enclosed space is higher. Then add on knocking down that corner of the existing house, and the cost per square metre of that bit of the extension is a LOT higher and the build is a lot more complicated. And that's before you even think about how modify / extend the roof structure, for which we really need a photograph of the back of the house as it is now.

We had a sun pipe in our last house to light the landing which otherwise had no natural light. It worked very well and lit the landing nicely. The internal bit looked like a large flush light fitting and we were often asked "where is the switch for that light?" Ours was a standard flashing kit on a 45 degree tiled roof so I can't unfortunately help with the zinc roof question other than have the sun pipe ready and get the roof installers to deal with it?

Are there any other houses planned in the area? i.e. is this plot 1 of 3 for example? If so don't be in a hurry, let the first build their house and pay for the upgrades.

The only bit about 3 phase that is significantly more expensive is a 3 phase distribution board costs more than single phase consumer units, and less choice. All the actual wiring will be identical single phase circuits same as if you had a single phase supply. If you choose a 4 phase PV inverter that will obviously be a 3 phase circuit.

Make sure the Cool Energy one is inverter driven, not all the Cool Energy ones are.

Flat panel LED lights are what you want, they literally fit in the width of a bit of plasterboard. You will need a bit of clearance for the mounting clip. Garages usually have plenty of height, so I would batten the ceiling with 25mm battens and then the plasterboard and that will give you plenty of clearance to route the cables and a bit of ventilation.

The Scillonian III is generally referred to as the Stomach Pump. I don't know why you would get sea sick on a narrowboat on a narrow canal with no flow, tides or waves. Unless you are transiting on the tidal Thames through central London.

If you can, I would visit the site and have a walk around and see if you are able to follow the wires to see how many houses are actually connected to that particular transformer. But definitely ask them to re quote for say a 12kVA single phase supply.

I don't know how far the map extends beyond the bit you have posted, but is is possible to work out how many houses that existing 50kVA transformer is feeding presently? In our street we were the 9th house to connect to an existing 100kVA transformer, and further down the street there is a 50kVA transformer feeding 5 houses. So i expect if there are 5 or more houses already on that transformer then it will need upgrading. But you might be able to argue you only need a low capacity supply. DNO's get nervous of heat pumps because older ones had a high start up surge, make it clear you will be using an inverter driven low power heat pump with soft start.

SSE are usually pretty good. They should provide you with a drawing showing what is going to be upgraded and what is going to be installed as new equipment. If you have that, then post it (anonymised) If you did not ask for 3 phase then definitely tell them you only need single phase. What are your intentions re heating demand? are you just going to build something that will scrape through building regs or are you planning a well insulated low energy house? do you have any idea yet how you plan to heat it?

Do you NEED 3 phase? Did you ask for it? Do you NEED 35kVA? That is a LOT for a single house. In my case I avoided any upgrade charges by accepting an offer of a single phase 12kVA supply which is proving plenty.

Looking very good. All the better for having a boat tied up, that plot needs a narrowboat.

Bonkers idea. If you are making such an extreme alteration to a house to add an extra floor to make it full 2 storey, just jacking up the existing roof would give you the wrong roof for the property. I would take the opportunity to do the job properly, completely new roof designed for the new job and take the opportunity to detail it and insulate it properly. The best you could hope for is to re use most of the roof tiles on the new roof if they are in good condition.

I recall this being discussed before. If an average EV does 200 miles to a charge, and the life of the battery pack will withstand 1000 charge / discharge cycles, then you have a car that will do 200K miles before the batteries are worn out, Not to dissimilar to what you can get from an average IC engine before it requires some serious work. But plug it into the grid and give them free reign to charge and discharge it at their whim, how much is your battery life going to be used up? Why would anyone choose to let the grid discharge your car battery, unless you are paid properly to compensate for the fact it may not always be full when you want to drive off and it may shorten the battery life?

Didn't I mention the deflection space requirement about 4 posts above?