Controllable heat source for SAP

[JohnnyB]

We are in the middle of our self build and I have just been told that I can't just have a wood burning stove in our annexe as the heat source. The sap guy has said the heat needs to be controllable otherwise the software will show a fail  It is a separate building so is being assessed separately to the main house.  It is a 130sq mtr 2 storey building that we are insulating to a good leave and as it isn't intended to be our main residence we thought a wood burner would be a cheap and simple way to heat it when it is being used.

 

If the building wasn't already up with the blockwork in place that creates the space for the stove we would probably say forget the wood burner and fit an ASHP but we seem to have gone slightly too far for that.

 

Does anyone understand what the SAP calculations need, or even better have ideas of ways around fitting a full heating system at this stage.  In the future we may want central heating but at this stage it isn't really need as well as the having a wood burner.

[nod]

You must of had an except able sap when you applied for planning What has changed 

[PNAmble]

What was your as designed SAP ? 

[JohnnyB]

We didn't have SAP calculations done at planning stage, or before we started to build. so wasn't aware of the need for heating controls until now.

[JohnMo]

 

11 hours ago, JohnnyB said:

controllable

Just make provision or install panel heaters, with time and thermostat control, cost to run isn't a factor if you have no interest in switching them on.

[Dave Jones]

put down an electric heater of some sort that passes sap.

 

never fit it.

 

crack on.

[ReedRichards]

Air-to-air heat pump?  Highly efficient and particularly good when you don't need the massive amounts of heat that a wood burning stove would give.

[JohnnyB]

We did discuss electric heating but he said that would be hard to make work as direct electric heating needs offsetting with solar, which we're not putting on the annexe only on the main house. 

If I combine @Dave Jones and @ReedRichards suggestions, specifiy a hear pump but never get round to fitting it, maybe we can get around it.

[JohnMo]

1 hour ago, JohnnyB said:

but never get round to fitting it, maybe we can get around it

They may/will ask for a commissioning certificate - so be prepared

[ReedRichards]

2 hours ago, JohnnyB said:

If I combine @Dave Jones and @ReedRichards suggestions, specifiy a hear pump but never get round to fitting it, maybe we can get around it.

 I still think it's genuinely a good idea.  With a wood burning stove you start off too cold, light the stove, wait an hour and thereafter you're too hot for a while longer than you keep feeding the stove.  It can be a very pleasant too hot but you inevitably end up hotter than you need to be.  The air-to-air heat pump lets you quickly take the chill off a space then keep you as warm as you want whilst using only a fraction of the electrical energy that you get back in heat.  

[JohnnyB]

@ReedRichards You are right that a heating system is more comfortable to live with and discussing it over the weekend we are coming to the conclusion that we should be fitting a heat pump, but when we were planning the build the intention was to put this building up cheaply and fit it out to a basic level to start with. We planned to use this as extra space for a games room/yoga studio/additional space when family and friends come to stay.  We were then planning to fit it out as a full house as we had time and funds to do so.  I have several years worth of free logs stored already and more drying so it is free heat. Most of the year it won't need any heat so lightling a fire when we want to use it seemed fairly simple.

 

As it happens timings haven't worked out as planned, we started building a lot later than expected and ended up building this buildng first. It's turned out to be a slightly quirky building and a space I really love that I can imagine living in once we want a smaller house, although my wife isn't so sure she wants to do that.  We will probably spend a year living in it while we build the main house that we are now planning to start next year. We have been discussing fitting an air source heat pump over the last few days and the plumbers are going to give us a price for that. We've already had UFH pipes fitted in the screed ready for future use so it would make sense to use those. From their initial estimates it will probably be about the same cost as fitting a woodburner as a reasonable stove and flue isn't a cheap option, especially as it needs to go through the airtight membrane.   The main issue is that several things have been designed around the woodburner being where it is including the staircase going round it and the walls of the 'chimney' surround supporting the 1st floor landing so the space for it can't be removed at this stage.