Performance based tendering

ECO_Mental

Guys & Gurls

I am currently pricing up my house at the moment and I know I want a low energy house but my problem is at the moment in Ireland if you want as an easy build process as possible this means going down the main contractor route.But a main contractor route in Ireland means cavity wall construction & traditional build methods, which means thermal looping cold bridges etc etc. Now I am not stupid (civil engineer by trade, built many a bridge... nothing to do with this I know) and I was thinking of going to project manage the build myself. Get a timber frame company to do superstructure and sub out the rest, not that hard but still a lot of work.

The other route is to go with my Arch and let him tender the job, but this leads to other problems. He has his ideas on how it should be built and his favorite contractors and he will spec it a certain way which will lead to more expense...... as this is how he thinks it should be built. Plus his fee.


What I am thinking at the moment is as a self builder, has anybody gone down the performance based tendering process by themselves. For example

I want
U value of Walls 0.13
U Value of roof 0.12
Air Tightness <2
No cold bridges in foundation
Windows U value 0.9
Etc, etc.

Is there any contractor in Ireland who will take this on??? Has anybody done this out there??? What are the pit falls???

Stuff it to the Man
E

Poor Uncle Tom

ECO_Mental wrote: »

But a main contractor route in Ireland means cavity wall construction & traditional build methods....

No it doesn't,
That's an over generalisation.

What part of the country are you hoping to build in?

beyondpassive

Recommend the Hybrid route, Main Contractor for Structural works, Self project management for fitting and finishing. So up to roof enclosure from main contractor, then airghtness, insulation, plumbing and HRV, sparks, windows, render, etc by local trades direct.

Well worth using the PHPP spreadsheet to model up your building and try out different combination's of specification to get the optimal level of performance to suit your budget. Sinnerboy on this forum is a certified Passive house designer and might be able to help you with some of the trickier aspects of PHPP as a modelling program. I have a full suite of CAD details of tried and trusted Irish methods of Passive build, using all available build methods. All have cold bridge calcs for head loss factor through the junctions. Happy to share those with you if you are considering going towards passive. The more people going this route, the better it is for all of us. We're all leaning together and also its good to reinforce the supply chain for the materials and components we are using. Just PM me your email address and I'll send them on. Usual caveats apply, for info only mind not for construction.

imitation

I`ll agree with Poor Uncle Tom, main contractors aren't all going to be block only houses. I know of one who has done a few timber frame houses and is looking into ICF. How many have decades of experience of this is another question, but I think if you can find one you can trust and who will adapt to problem it should be doable.

Tefral

Why dont you tender it on Meat Criteria?

Say 60% Price and 40% Meat criteria based on, programme, previous experience in this particular area etc.

ECO_Mental

Well I am building in Cork and I was going down the hybrid route getting the superstructure done by a timber frame manufacturer and get them do the foundations as well (some of them do) and rest would be done in packages supply and fit windows, supply and fit all electrical etc

But this was getting complicated and I had a few drinks yesterday and had a brain fart and thought wouldn't be easier to just spec a performance and let a main contractor do all the donkey work to ensure he reaches the performance criteria. But having a sober head on me today I dont know would this work I think it might mean more work. Like going through a proper tendering process and setting out MEAT criteria etc etc ensuring everything is airtight in the tender docs because as sure night follows day the contractor would find something I have left out and I am left bent over a barrel taking it.

Unless any of you out there think it feasible and could work. I think also it would be hard to find any contractor to take it on.

Anyway I'll struggle on like a poor farmer.....
EM