Smallholdertoo

In a word No! Although it s only a periscope of sorts , it needs to be a1rtight and thermally functional and aesthetically attractive both internally and out. Maybe worth the effort if i needed 5. Thanks for your help.

Contacted Monodraught. They agreed that their Sunpipe is not designed to be airtight, Solatube however do have a passiv house standard version of their product that has 0.5w/m2k u-value and gaskets to ensure that airtightness. So I am probably going down this route.

Many thanks I will contact them on Monday

We are due to start building a highly insulated 1.5 storey detached annexe in July. The downstairs wet room of approx. 4m2 is due to be lit by a small Velux in the roof at the edge of an upstairs. bedroom. I now need to use this area in the bedroom behind a bulkhead for MVHR pipes. My wife wants to have natural light in the wet room so she is suggesting a sun pipe. For me this will only work if it is well insulated otherwise condensation, due to cold bridging, may be a problem. We will have a number of Velux's on the roof so I thought that perhaps a Velux sun tunnel may work. However, these have a basic u-value of 2.9w/m2/k, though they do an insulation kit which drops the u-value to 1.8w/m2/k but only for the 14" version which would be too large for the size of the room. Has anyone used a Velux sun tunnel in a bathroom environment? and if so was there a condensation issue? Or does anyone have any other suggestions?

Thanks for the comments and the support. The SE is yet to confirm the thickness though he has mentioned 250mm in the past. If it does turn out to be 250mm any thoughts how to persuade him to let it be thinner? Its probably worth mentioning that in readiness for the build we have installed 11kw of PVs and 20kw of battery storage on a new shed. This will provide the power to the new house. would this affect your choice of ASHP

We are due to build a small very well insulated 1.5 storey timber frame house later this summer. Using the Jeremy Harris spreadsheet, the house will have a thermal demand of under under 2kw when it is -10c outside . U values of 0.09, 0.13 and 0.10 for the roof, walls and floor respectively. The house has passed Part O for overheating and will have MVHR. We are now definitely going to have an85m2 insulated reinforced raft. I want to have ufh in the raft and in line with what others have done on this site it will have 3-4 loops, a singe zone and one thermostat. We will have a small ashp perhaps 3.5-5kw. I expect water temperatures in the ufh will be under 25c. The ashp will also provide our hot water - a 250l unvented cylinder. I keep on being given the advice that a 250mm slab will be very slow to heat or cool e.g. from my designer "My concern with a heated slab of 250mm thick is that the response times will be so slow that you will find that you are unable to adjust internal temperatures when the house heats up to the required temperature and then continues to heat when you don't want it because of the thermal mass." I am aware that the raft will be slow to warm up and cool down but am I right to believe that with the weather compensation a single thermostat and a low water temperature I am unlikely to have the issues suggested re overshoot? It would be great to hear from those on the forum that have thick rafts, ufh in raft and a well insulated house . Thanks in advance

Thanks everyone for your comments. I have just spoken to the TF company and they confirm only the internal stud needs to be on the slab, the rest 160mm can be supported by the insulation. So we will be going insulated structural raft route.

We are due to build a 130m2 near passiv house timber framed 1.5 storey house with a brick plinth in the early summer. We decided to go larsen truss timber frame I was hoping to have a highly insulated structural raft (u-value .10) with UFH in the raft but now my designer has been informed by the SE that the larsen truss will be structural both on the outside and and inside studs so will need to be fully supported, He had initially assumed that only the internal stud would be structural which would have allowed the non structural outside stud to cover the insulation between the brick plinth and the slab. This change produces a cold bridge as shown below in blue. He is now suggesting that we should go with strip or trench foundations and a slab as shown in the drawings below. I am concerned that there will be cold bridging and a u-value of.10 may not be achievable. Any thoughts on his suggestions and how they can be improved or how we can still use a insulated raft?

We didn't need to use British Gas as when Octopus rang, we explained that National Grid should be fitting the supply on the 12th of December. The man from Octopus replied that there was an appointment for the 13th if that would work for us. So hopefully we should have a supply in 3 weeks. Thanks for your help Sometimes I just worry too much!

What was the lead time when you put in the order to when the meter was installed?

Our 3 phase 42kVa supply is due to be installed on 12th December. It is to be installed in a new stable shed but will power our new annexe when it is built. On contacting Octopus I was told it will be more than 4 weeks before the smart meter can be fitted. I will find out the first available fitting date tomorrow. I believe that when you swap electricity suppliers you now do not need a new smart meter. I guess, I could get one of the other other electricity suppliers to fit the meter and then swap to Octopus once meter installed (and new PVs are on the roof). My question is - Does anyone know of other suppliers that are quicker to install 3 phase smart meters ? Thanks for your help, in advance.

@nod What are the main causes of the damage? - contact with the Power float, scuff damage from boots etc. and how to best avoid if determined to have UFH pipes in the concrete slab ?

Many thanks for your responses - Luckily the concrete will not be the finished floor. We will be tiling over it! Are you aware of any youtube videos that show this?

As this is something I have never done, does shuttering off the area work for a reinforced raft? The drain will be at an edge rather than the middle. How did you do yours?

I guess the intention will be to tie the pipe to the rebar that will be 200mm apart. Would it help if the manifold was pressurised with water? I accept it will be slow to change temperature . Thanks for your comments.