Bitpipe

We're probably a bit unique in that because we built a basement, we didn't take the slab element from MBC - that said, we found it straightforward enough to mimic the MBC passive slab detail (200mm EPS, 300mm RC) in the basement walls and we went for a timber suspended floor, provided by MBC by designed by our basement SE. We had MBC work off the SE's drawings and they did a final on site measurement of the basement box before our frame went into production. A few of the 10m steels that made up the floor were slightly too long but it was easy enough to widen the pockets we'd formed in the walls and all was good. Follow on trades, especially the tackers were very complimentary about the quality of the internal framing and battening - made their life easier. On the PB sub thread above, our tackers just moved all the board they needed into place as it arrived - they even made shifting the sound block board look easy

Also, be quick to clean the baths of spills - kids one has a stain on it from some bath product the daughter used and didn't wipe off. They supply a light abrasive sponge to clean such stains.

The kids shower is a Lusso stone (1650 x 700 from memory) - only 25mm thick so by the time we made up the rest of the floor with 6mm backer boards, electric UFH, latex and porcelain tile, it was completely flush and looks great. The bath plug waste is fine (ask for matching resin ones, look much better than the chrome) but the fittings underneath were rubbish. One was narrow enough to sit under the bath in the small space available but quite narrow diameter and would have taken ages to empty. It also was a concertina style to 'make your own trap' but the plumber was very wary of using. Tried HepVo also in a horizontal arrangement but that was not shallow enough either and does not work well that way round, can get hair etc suck in it and be held open. In the end we bit the bullet and chopped a section out of the floor and put a proper trap on the bath, with a wide bore flex section to meet the first fix waste. Put a generous bead (10mm) of SikaFlex around the cut out to stop any splashes finding their way down there. Was not happy cutting into a freshly tiled floor with electric UFH and tanking in it, would have been better if we'd planned for that and made proper provision, but worked out ok in the end. For shower screens, I bought 8mm all channel and had my joiner mitre the ends, sikaflex and screwed to the tiles. Then ordered some made to measure 8mm glass and sikaflexed that in - looks great and only cost a few hundred for both showers, vs the big prices I was seeing for cubicles.

I believe HerbJ has a Paul system, professionally installed - not that active on the forum but will probably respond to a PM. Many here have done it DIY, not that complicated in the grand scheme of things, most of the hard work is making allowances during building design for duct runs (both large and small diameter) and location of the unit. Many here have used BPC, an independent and very helpful supplier based in NI - I have a VentAxia Sentinel system from them that serves a near 400m2 house - self installed and seems to work (although not formally comissioned. Others have used more sophisticated units from Genevx with active heating and cooling functions.

While I may have erred on the skimming, we tanked the crap out of the bathrooms following Nick's guidelines on installing shower trays etc. Also went full Impey on the wet room floor.

That's good to know, will try and get this for any variations in advance of submission as our LA are very slow to reply - 30 days is very tight.

Yes, I was told this after the room had been skimmed but we used 600x300 porcelain tiles and they went on fine.

This is good to know and now I'm a bit worried. Our basement was shown internally on the planning as an open box, but we made it into 4 rooms. Not sure if this will cause a problem with VAT reclaim, bot in general for the claim and the basement itself. Most of the fit out work there was zero rated but I was still planning to claim VAT on the timber for partitioning it, doors, skirting & architrave. We also put in glazed doors (which need VAT reclaim) between living room and study on the GF that is not in the planning drawings. Given plans can change during a build, without needing recourse to the planning dept, how are these best presented to the HMRC?

Sorry to hear about this Jack, can only imagine how upsetting this is. We used waterproof (green) pb in the bathrooms and had it skimmed before tiling, tanking shower areas first - seems to be pretty bombproof, as evidenced by the difficulty we had in removing some tiles to find a leak. Only used 6mm backer boards on the floor and these had UFH mats and then latex before tiles - these ones used the washer & screw system and I was surprised at the number of fixings the tiler used.

This thread is becoming worthy of a Pythonesque Four Yorkshire Men style sketch...

Agree Jeremy, we have quite a long garden so plan for now is to level and turf the area immediately behind the house (which currently has veg patches and greenhouses ) and then work on getting the levels correct around the house before paving to get the BR completion cert Work to the front (drive way, walls, gates etc) will have to wait - at some point I'll need to make the decision when to pull the trigger on the cert and then VAT rebate to release some funds. Hoping that remainder of work can be supply & fit and still at zero VAT as any material purchased thereafter will not be VAT reclaimable.

Just upgraded to one of those this week, gives a space for people to kick off their shoes without blocking the door.

12ft x 38ft, two beds. Roomy inside but our lane is barely 12ft wide!

As with most things self build, temporary feeling of happiness then a dawning realisation of what's next plus no longer having the excuse of why having the van there was preventing progress.

Turtlemats are the answer - only a few mm high and trap dirt very effectively, plus you can wash them in the machine. We have a huge one under our RK front door and there is only a few mm between that and the resin floor.

Remember you need around 10mm door clearance (depending on width) for MVHR if you're having it..

From experience, probably the whole ground floor erected, although we had them in November so they were working by headlights for a good bit of the day so probably slowed them down somewhat.

It was a tight squeeze but we got it out the opposite side of the site that it came in on. Ended up selling to the caravan mover as I kept getting messed about by other self builders. Hard to believe that it's been on site for nearly 3 years and we lived in it for 18 months. Can't say I was sad to let it go... Can start work in the back garden now (funds allowing)!

Here comes the science bit.... "The switches and PIRs are basically just wired in parallel, the boost connections only usually give you the switching pair but the PIRs require a neutral so picked that up from the MVHR unit and then wired the whole lot by daisy chaining between each point with 3 core & earth with the neutral just connected through (separately to the local lighting neutral to avoid RCD tripping) in each conventional switch. The switches are double pole switches so that the local light switching is in one side of the switch and the MVHR boost in the other"

We have the 'auto boost' in the 4 bathrooms and the MVHR controller, which has a boost function, in the utility. Our cooker hood is not compatible with the cooker hood mode of the MVHR so theres a plan to put a current sensor on the supply for that to work. On our MVHR, any boost signal runs the boost for 10 mins, you can't turn it off.

Boost airflow is marginally noiser - you actually only really notice when it switches off if that makes sense. Not sure how the electrician wired up all of the PIRs and light switches to activate boost (and also the secondary pump, both work off the same switched live), but can ask him.

Yes, we have a TF house that's roughly square (11.5m x 10.5m) and decided to have a full basement under the house which acts as the foundations. Planning didn't blink so we got an additional 107m2 internal floor area, nearly 50% extra on the above ground element, which in the SE is worth quite a bit. Architect was very wary (had no experience) but it was no problem to build and is one of the best features of the house. All the plant is down there in a dedicated room and we have four large (4mx5m) rooms each with light well for leisure use. Nice bright spaces, really pleased we went with it. Cost wise, structure was £120k but that included the demo, clearance and plot services, so probably closer to £100k just for the basement - you could probably subtract a good chunk from that had we used a traditional raft slab. Fit out was about another £15k, kind of got lost in the overall electrics / plastering / joinery / flooring budget. Aside from plant, there are no wet services and no heating required (we have 300mm insulation under the slab and 200mm outside the walls. We used warrantied waterproof concrete (Sika) and no other internal tanking or external membrane as the water table is fairly low (6m). I see that you're near water so the situation may be different. There are 3 recognised forms of waterproofing - best practice is to use two but we got by with one (B). A is external membrane - needs very careful application and extreme care on backfilling, otherwise it can be compromised B is waterproof concrete - we used a Sika system of admix and waterbars in the joins - was all recorded, inspected and signed off on site by a Sika rep who then issued the warranty. C is internal membrane - applied to the internal walls and drains to a sump with a submerged pump (or two for redundancy). Quite common in London basements but has an ongoing maintenance cost wrt the pump. About 30% of basement cost is muck away and a tight site with poor access will increase costs further. A good chunk of the remaining build cost is formwork labour (took 2-3 days to prep for each pour) so complicate designs will cost more to form, the actual concrete is not that significant a cost. We were lucky with our design, location and conditions. Many 'basement specialists' are focused on the conversion market (London dominant) so are not suitable for a new build. There are specialists (Glatthar) who are high quality but fairly expensive. Most competent ground workers can build a decent basement, especially if they sub out the concrete works to an experienced team who can work with a warrantied product. These people build carparks and the like all day long so this is small beer. You could even chance an experienced general builder if they use a warrantied waterproofing product.

We used Gaulhofer Inline 91 Slim, passive certified and a very low profile, even less on show after rendering. May fail your low cost requirement though... https://www.gaulhofer.com/uk/windows/wood-aluminum/inline-91-slim

Ted, your questionnaire is geared towards construction industry. The majority on this site are self builders so your response rate will be low. Why not create something more relevant to our community and I'm sure you'll get a lot more feedback.

Get MagicMan to fix it. My son dropped a screwdriver in a stone resin bath and for good measure the plumber chipped the edge on install. Local guy came out and did an invisible repair. I also got him out to repair a resin stone sink that got cracked when we had to remove it from the wall to repair a leak. http://www.magicman.co.uk