Challenges left to solve in house construction?

[andrewhockley]

Isn't some airflow required though to prevent condensation and damp, especially in new builds where they're more like sealed boxes than the old stuff?

Well you need airflow, but not airflow from leaky windows and doors and skirtings, because that means you are losing energy. Airflow needs to be through MVHR and heat exchanger - you then have no problems with condensation/mould

 

[IanW]

Exactly, which as you have suggested, requires attention to detail in the build process to ensure all possible gaps are filled.

Great to see more and more people interested in this, and especially builders. like Andrew, making it happen.

 

[blossomchris]

I think the onus on specifiers should be to avoid designs that can be messed up, as far as is possible. I have yet to find a plasterer who can be trusted to install dot and dab plasterboard to avoid leaks, so rather than checking every board going up I specified wet plaster on the latest houses.

A house I worked on a few years ago, the walls plasterboard was adhered to metal firrings, which were adhered to blockwork with gyproc adhesive. The boards were backed with urethane and over 25m/m thick, and screwed and glued to the firrings. At all perimeters, floor, ceiling, reveals and door openings a seal was applied.

The void between blockwork and the boards, contained the wiring and acted as a 2nd cavity.


Bloss

 

[davidsrsb]

That must really start to eat into the square footage of a small roomed modern house

 

[blossomchris]

That must really start to eat into the square footage of a small roomed modern house

It does, but not as much as you think.

Convential plastering will add approx 25m/m to blockwork.

Firrings and urethane board take up approx 55-65m/m, but bear in mind, because the system is insulation as itself the block work can be of a lesser thickness, so in total this system may use an additional space of 15-25m/m only, per external wall.


Bloss

 

[stevec67]

There should be a severe limit on green belt development until most brownfield or contaminated sites are remediated and redeveloped. The uk should stop pussyfooting around on this. There is a clear principle that the polluter pays and this should be enforced.

Good in principle but demolition and cleanup can far exceed build cost, I understand. As for polluter pays, I know a dairy I used to work at is an old Victorian tannery. The pollution levels underneath the buildings are horrific, so remediation is hugely costly. You can't go after the dairy, it's not of their doing, and the tannery no longer exists, nor has done for 100 years. This is one reason why a plum site a mile outside Leeds city centre is used for cheap yard rent and a bit of truck maintenance.

Furthermore there should be an enforceable minimum size for new build dwellings.

I disagree. The limiting factor for dwellings is not size but packaging. You can live comfortably in a caravan, if it is well organised, dry and warm. Large houses are great, but they need to be paid for on an overcrowded island.