2017 What worked and what didn't

[SteamyTea]

So a week to go until the end of the year.

Anyone willing to post up what worked and what didn't on their building projects.

Preface it with 'Worked' or 'Not Worked' and then a brief description.

You can follow it with a long rant if you like.

Edited December 25, 2017 by SteamyTea

[Jeremy Harris]

Didn't work:

 

1.  Complicated heating controls, after many months of playing with weather compensation, controlling the house temperature using the floor slab temperature and assuming that the logical link between floor temperature and house temperature would work well at controlling the latter using the former, I realised that, as the heating system only provides a small part of the total house heating, it would never work, so I gave up and installed a very simple room thermostat, which works very well.  Should have done this in the first place.

 

2.  Water filled thermal store.  No matter how much extra insulation I added around it, the heat losses from it were still very high, over 2 kWh per day (as supplied, with a double layer of insulation, the losses were over 3 kWh/day).  This cause the services room to get up to around 40 deg C in summer, damaged the oak door between it and the bedroom and caused the adjacent bedroom to badly over heat.  Swapping the thermal store for a Sunamp PV, with it's massively lower heat losses, completely fixed the problem, and freed up lots of room in the services area, too.

 

3.  Complicated ozone injection and flow rate control system on the borehole feed.  It worked, but was far too complex and has now been replaced with a much easier to service, very simple eductor, that is far more effective at adding and mixing ozone to the incoming supply and also easier to service and repair.  The brass eductor took two goes to get right, but has no parts to wear out, no flexible seals and should last forever.

 

Did work:

 

1.  Choosing an insulation system with a high decrement delay factor.  Not only does it significantly improve the comfort level in the house, by helping to keep the internal temperature steady, but it has the added bonus of being an extremely good acoustic insulating material too, so improves the soundproofing and deadens the internal acoustics a fair bit (handy in a house with a lot of hard surfaces).

 

2.  Opting to have UFH inside the insulated concrete slab.  This forms a nice big "storage heater", yet responds pretty quickly when needed.  Having a heated (or cooled) power floated slab that was flat and smooth enough to lay flooring to directly saved a lot of hassle and money.

 

3.  Choosing the more expensive Genvex MVHR with the internal air-to-air heat pump.  It's not massively effective, but does do a pretty good job at keeping the bedrooms a degree or two cooler than downstairs in very hot weather.  It also does a great job of drying out towels or washing left on the drying rack in the utility room.

 

4.  Avoiding the use of highly paid consultants etc whenever possible.  I found that, with a bit of effort, I didn't need to use many at all.  It seems that when you are self-building a house every Tom, Dick and Harry comes at you with their hand held out for more of your hard-earned cash - you can avoid paying out a lot of this with a bit of determination and time.

[Visti]

Just now, JSHarris said:

1. Choosing an insulation system with a high decrement delay factor.  Not only does it significantly improve the comfort level in the house, by helping to keep the internal temperature steady, but it has the added bonus of being an extremely good acoustic insulating material too, so improves the soundproofing and deadens the internal acoustics a fair bit (handy in a house with a lot of hard surfaces). 

 

I take it that is the 300mm cellulose insulation? Or did you add additional layers in the end?

 

Just now, JSHarris said:

3.  Choosing the more expensive Genvex MVHR with the internal air-to-air heat pump.  It's not massively effective, but does do a pretty good job at keeping the bedrooms a degree or two cooler than downstairs in very hot weather.  It also does a great job of drying out towels or washing left on the drying rack in the utility room.

 

I'm finding it difficult o justify double the price vs a Renovent Excellence 400; does the heat pump make such a difference?

[Jeremy Harris]

6 minutes ago, Visti said:

 

I take it that is the 300mm cellulose insulation? Or did you add additional layers in the end?

 

 

I'm finding it difficult o justify double the price vs a Renovent Excellence 400; does the heat pump make such a difference?

 

 

Yes, it's 300mm of cellulose in the walls and 400mm of it in the roof.

 

Rather than the Genvex, if you have a source of cool water (say, from a heat pump) then you can just fit a duct heat exchanger, one of the ones with a condensate tray.  It would probably work just as well, and with hindsight that may well have worked well for us and been cheaper than the Genvex by a fair bit.  However, we did buy the Genvex direct from Denmark, so the true cost was not far off half the cost the UK supplier wanted.

 

In hot weather, it does definitely help to keep the bedrooms cool, and for us that makes it worthwhile.

Edited December 25, 2017 by JSHarris

[Ferdinand]

25 minutes ago, JSHarris said:

 

 

Yes, it's 300mm of cellulose in the walls and 400mm of it in the roof.

 

Rather than the Genvex, if you have a source of cool water (say, from a heat pump) then you can just fit a duct heat exchanger, one of the ones with a condensate tray.  It would probably work just as well, and with hindsight that may well have worked well for us and been cheaper than the Genvex by a fair bit.  However, we did buy the Genvex direct from Denmark, so the true cost was not far off half the cost the UK supplier wanted.

 

In hot weather, it does definitely help to keep the bedrooms cool, and for us that makes it worthwhile.

 

Is there a link as to what your Genvex does extra, @JSHarris? Do I just go blog digging?.

 

Just set the LBB to 20c with the heating on continuously for the next week, and taken meter readings which will give me some numbers.

 

F 

[Visti]

If I'm not mistaken it's this Genvex 3 unit (or similar) from Sundhus.dk, isn't it?

 

Fyi; if anyone needs clarification or help with Danish even with Google translate and their excellent English, feel free to reach out to me. Being a dual citizen has its benefits!

[Jeremy Harris]

6 minutes ago, Ferdinand said:

Is there a link as to what your Genvex does extra, @JSHarris? Do I just go blog digging?.

 

 

Essentially it's just a normal MVHR unit with a reversible air-to-air heat pump built in, so it can add around 1.5 kW of heat to the fresh air distributed around the house or remove around the same amount of heat by pumping cool air into the fresh air distributed around the house.

 

The main advantage is that it's a "single box" solution, that is installed in exactly the same way as an MVHR unit, with no additional ducting, plumbing or wiring connections.

 

The main disadvantage is that it is really just a comfort cooling unit, or heating for a house with a low heating demand (it would happily keep our house warm in winter on it's own), and isn;t well suited to use in houses that are less well insulated or airtight.

[Jeremy Harris]

2 minutes ago, Visti said:

If I'm not mistaken it's this Genvex 3 unit (or similar) from Sundhus.dk, isn't it?

 

Fyi; if anyone needs clarification or help with Danish even with Google translate and their excellent English, feel free to reach out to me. Being a dual citizen has its benefits!

 

Ours is the Genvex Premium 1L, slightly over-sized for our house, we could have used a Premium 1, but the additional cost for the 1L was small, and the additional capacity is useful.  Here's a link to the Danish supplier we bought ours from: http://www.sundthus.dk/genvex-ge-premium-1l-hoejre/

[jamiehamy]

Worked - Sheet metal decking for garage roof. 

 

Engineer had selected 3 mahoosive  beams to span 7m (garage width) with three separate sections of block n beam spanning between them (in 3m5m sections) , to be topped with a structural topping. Very expensive and labour intensive. Opted for sheet metal decking which spanned the 7m, tek screwed together and hit fixed to the walls. Rebar in the troughs, A252 mesh on top and a 270mm slab. Really straight forward to install, roof in a day, rebar in a day, propping half a day, pour concrete half a day. 

 

Didn't work - taping and filling. I had a go in the kitchen and whilst to the casual observer it looks fine,if you shine a light certain ways, it's crap. At least I had a go, but glad I got the rest of the house skimmed. Wisdom on here recommended against tnf but I had to have a go. Best left to experts! 

 

 

 

 

[Construction Channel]

Worked: making a plan of what to complete in 2017

 

Didn't work: fulfilling said plan......  

[Oz07]

Didn't work - appendix

worked - having it removed!

 

17 been crap in health and business but few irons in the fire already for next year and feeling good. 

[RandAbuild]

Things that worked

• Getting into the foul drain by having external soil pipes. I knew our levels were going to be very tight, but until we made the final connection, we were unsure how tight. We had measured the invert level of the drain we had to connect to (which was about 12m from the house) and concluded that internal SVPs were not going to work without a pumping station somehwere. So we introduced external Soil pipes on either side of the house, which would not be visible from the front. In the end, we had about 10mm to spare. This saved us in the region of £3k, as well as avoiding the pain of having to do regular pump maintenance. Always use gravity if you can!
• The MVHR. With easijoists, it is very easy to install an MVHR system and I think all the benefits far outweigh the costs. No bathroom fans to deal with or trickle vents that lose heat. A managed passive ventilation system that virtually no maintenance is an essential. But you do need good levels of airtightness.
• Underfloor heating. Although we haven't moved in yet, we've had the heating on a tickover setting and it's clear it is going to be fantastic - consistent, controllable, uniform heat throughout the house

Things that we'd do differently

• Watch out for messy bricklayers. Our brickies were incredibly messy, leaving piles of broken bricks and mortar all over the place. It took me the best part of a day to hack off the snots from the scaffold poles. This would have been so much easier if we had put down down groundsheets and taped the ends of the poles.
• Try to get subbies to hire in the plant they needed, rather than paying for it yourself. We didn't have a main contractor and ended up paying £1600 of VAT that can't be recovered on plant hire. This goes for scaffolding too.
• Keep it simple. We used a Jetfloor beam and insulated block floor. It was fairly cost-effective but I'm not sure it has many benefits over a traditional beam and block with 300mm insulation construction.  Also think about when your underfloor heating and screed will be installed.
• Use SIPs for the roof, especially if like us you have rooms in the roof. A traditional raftered roof is time consuming to make airtight and well insulated. I think SIPs could offer a much more simple solution.
• Make sure to think whether you need any holes pre-cut in your steels. We have one large RSJ running across our living room. As soon as it went in, I thought how are we going to get the MVHR ducts through that! I considered using a magdrill to cut a couple of holes (no room) and even taking it out to cut them (very time consuming and difficult). In the end we went over the top into boxed in areas, but it would have been so much better to have thought about it before, or use a castellated beam.
• Understand that good subbies will be busy. They'll always have a lot of work on. Hanging onto them means being patient and expecting they'll screw up any notion of planning and coordinating trades that are inter-dependent.

 

 

[joe90]

WORKED

 

using a very good local builder with an excellent reputation

 

DIDNT WORK

 

cant think of anything ( yet) 

[RandAbuild]

May 2016

 

Nov 2017

 

 

Edited December 27, 2017 by RandAbuild
Wrong date!

[Ferdinand]

5 hours ago, Oz07 said:

Didn't work - appendix

worked - having it removed!

 

17 been crap in health and business but few irons in the fire already for next year and feeling good. 

 

Intrigued by what a 'working Appendix' actually does. 

 

/nitpick.

Edited December 27, 2017 by Ferdinand

[SteamyTea]

It is the bit at an end of a project to put the errors right and show extra data.

[mike2016]

Worked:

• Bought a plot by buying the whole house attached to it....
• Went down for a cup of milk before bed time and caught massive developing leak from upstairs toilet cistern overflow (Pipe not connected to anything!)
• CCTV installation, 4 external POE cameras and DVR
• Buying my first set of DIY kit throughout the year.....so THAT's what they use that <insert tool name here> for....!!
• Asking silly questions here, getting terrific answers
• Purchasing Home Designer CAD software to help me visualize new house plans and spaces
• Getting to grips with removing wallpaper, laying laminate flooring and painting walls to freshen up the existing house

 

Didn't Work:

• Putting three screws through the upstairs hot water pipe when tackling floorboard squeaks
• Installing valves onto toilet cistern feeds without subsequent leaks
• Pressure sensor and fan fault on condenser gas boiler just after 2 year mark and out of warranty, right before cold weekend spell.....(plumber saved the day though)! 

[daiking]

Things that didn’t work in 2017: my work ethic.

 

roll on 2018

[Visti]

What worked

• Reserved our desired plot in Oxfordshire following many years of searching and waiting for Graven Hill
• Found ourselves a great architect that has designed us an excellent house and have helped us immeasurably.
• Signing up to this forum and getting some stunning advice. Most notably on our costing estimates.

What didn't work

• Price of our plot was ~£30k above our expectations, cleaning out out original contingency before we even began.
• Spent £780 on a Quantity Surveyor which could have done better by ourselves using SPONS (lesson learnt!)
• The planned budget for the house build has had to be increased by about 20% overall due to material price rises following the Brexit vote.
• Submission for PP didn't get through before the end of the year as planned, pushing out build out by at least an extra month.