LnP

I'm a bit concerned that external Venetian blinds will get dirty and dusty and be difficult to clean. Any issues with this? I looked at these external screens at the NSBRC and they look quite interesting https://www.solar-shield.co.uk/microlouvre-screens. You can see through them but they claim to screen out enough to control solar gain.

Hmmm. Food for thought. I plan to self manage and have as little hands on the tools myself as possible. I'm fairly well plugged into a network of good local trades who've worked for me before (not a full self build though) and have told me they will be happy if they're invited back. I have a friend who's a builder and is happy to advise and get me out of trouble. Tricky when you don't know what you don't know though. I've had quotes from four timber frame companies and asked them all the same open question, what will be left for me to do when you leave the site? And I've tried to estimate the value of the different scopes to compare the quotes on a similar basis. I suppose this is what the contingency is for? I'm in Cheshire. I'd appreciate any advice you can share. I'll drop you a DM.

They quoted for 0.15 U value external wall ULTIMA 90/50 (TW55/TW55) system, factory fit insulation between the studs, a VCL, a secondary insulation layer across the studs, and a service void batten. They also offer an upgrade to 0.12 U value external wall - ULTIMA 140/50 (TW55/TW55), which we would take if we go with Potton. The leak tightness they "target" is the same regardless. I agree, 5 is not sufficient. They said we could make the target 3, but I'd have to check my notes whether they proposed a charge for that.

I have a quote from Potton (but we're still wrestling with planning🫤) which says "You have not advised your requirement so we will be targeting 5. We will achieve this air tightness through the external walls. Air tightness of the overall structure is a combined responsibility between the principal contractor and all trades". Actually I have advised I want better than this and they are prepared to "target" 3. Did you have any expectations about what airtightness you'd get from them?

Catch up! He was talking about condenser dryers 😀. ... about which I didn't know much until this voyage of discovery.

Well, I think I know that you didn't read my post. I was talking about condenser dryers. The ~ 2.5 kW heat from a condenser dryer all ends up in the room .... well tbh all the heat from your heat pump dryer's compressor motor ends up in your room as well, however much that is 😉.

Indeed, I understood the heat exchanger bit, but I was confused about what air went where! The room air just blows over the condenser and then goes straight back out into the room. If your tumble dryer has a 2.5 kW heater, all the 2.5 kW ends up in your house which is maybe a good thing in winter. If you can move that heat into the rest of the house, you'll save on heating bills and if it reduces the temperature of your utility room, the condenser will work better and you'll dry your clothes faster. The guy in the linked YouTube video isn't a fan of HP dryers and agrees with what @Nickfromwales says about drying times ... link. Sorry if this hijacked the thread. I know a lot more about tumble dryers now 😀.

Interesting. I wasn't sure what would be the cold surface the moist air was condensed against. Just did some Googling and they have a heat exchanger where the hot moist air out of the dryer exchanges heat against the colder incoming air from the room. Thinking about the heat and material balance around it - since the condenser is being cooled by incoming air from the room, there must be air going back out into the room which has got to be hotter and moister than what went in. Maybe that hot air is OK in winter but not what you want in the summer if you're concerned about over heating? And once that warm moist air coming out of the dryer cools down, do you get condensation in the house - maybe not a problem in a typical British drafty house but more of an issue in an air tight self build? @Nickfromwales says that HP dryers have long drying times, that must be simply to do with the size of heat pump they use. In principle, you should be able to condense more water out of the air on the cold side of a heat pump and sent it back into the dryer with less moisture still in it. Or is there a design problem balancing the size of the cooling/condensing and heating sides of the heat pump? I'm still a bit confused!

Am I right in thinking that if your tumble dryer is not a heat pump one, it needs a vent to the outside? If so, is that a problem for achieving good structural leak tightness?

I'm not familiar with one of these, but are there other hazards you need to address? Asbestos? Electricity supply isolation? Gas supply isolation?

Looks like lots of current and ex landlords on here. I've thought about it but largely through inertia never got round to it ... but is it a good investment? I've often wondered, if you put all of the expenses, rental incomes and capital gain into a discounted cash flow, what annualised return does it yield? Investing in a plain Jane MSCI World Index ETF over the last 10 years would have yielded an annualised before tax 11.7%, with none of the hassle.

Not caused by renewables or lack of inertia.... "The ultimate cause of the peninsular electrical zero on April 28th was a phenomenon of overvoltages in the form of a "chain reaction" in which high voltages cause generation disconnections, which in turn causes new increases in voltage and thus new disconnections, and so on. This phenomenon was preceded by large amplitude voltage variations in short periods of time throughout the morning." "Therefore, it is highly probable that, in a scenario of greater inertia and therefore a slowing down of the frequency drop, the "surge wave" would have caused the "cascade effect" in any case, causing a significant part of the generation to drop and thus overcoming the response capacity of the underfrequency protections.." Spanish_blackout_report_1750239802.pdf

Good to know. Thanks for sharing. And this PCC is issued by an FRCS, so a member of one of the approved professional bodies.

The professional requirements are listed under 6.7.4 here. But maybe the people CMLC sends out are members of one of these professional bodies?

@nod your screenshot with PCC at the top suggests it's a Professional Consultant Certificate and not a Structural Warranty. The post linked below discussed the difference and that a PCC might not be accepted by a lender, which if it were true would make the house hard to sell. On the other hand, there are comments in that thread that some lenders don't require either. I'm sure you looked into this. What are your thoughts?