Garage ventilation/MVHR

[SuperJohnG]

I have an integral garage in our build. The wall make up is the same as the rest of the house (SIPS). Full house is an insulated foundation. There is a thermal break between garage and main house by way of 50mmm piece of insulation  so the garage didn't drag heat out the rest of house. 

 

Garage has UFH albeit wo t be turned on, I done this to allow for future planning to turn it into a new room for kids for games or a bar or some thing. 

 

I'll eventually build a big shed up the back for garden stuff and cars etc. 

 

Currently my dilemma is i need to ventilate the garage as per scottish buildings regs, on my drgs as through wall vents to provide cross ventilation, im reluctsnt to do this as itll spoil the loom of the very expensive silico ce render system and it just punches a big hole I'll not need in future when converted. Now my BC suggest speaking to MVHR guys and seeing if I can use that to ventilate it but reading other posts that can't be done and also complicates it being outside thermal envelope currently, I do have an insulated garage door but it's by no means airtight. 

But interested to hear if anyone has had a similar challenge? 

 

I was considering just renaming it workshop which would remove the ventilation requirement around exhaust gases and I could then use MVHR, albeit maybe not connect it just now. Or am I just setting myself up for a condensation nightmare there? 

 

[JohnMo]

Have you looked at a dMVHR, one unit in the wall.  These are generally run based on condition.  Would keep BC happy and would be future plans proof.

 

Quite like these, although not used one.

 

https://ecostream.org.uk/d-mvhr/

[JohnMo]

Just read the regs.  Not sure it is allowed to be connected to the mvhr anyway (second bullet below b.)

 

Small garages - garages of less than 30m² do not require the ventilation to be designed. It is expected that a degree of fortuitous ventilation is created by the imperfect fit of ‘up and over’ doors or pass doors. With such garages, it is inadvisable for designers to attempt to achieve an airtight construction.

 

 

A garage with a floor area of at least 30m² but not more than 60m² used for the parking of motor vehicles should have provision for natural or mechanical ventilation. Ventilation should be provided in accordance with the following guidance:

1. where the garage is naturally ventilated, by providing at least 2 permanent ventilators, each with an open area of at least 1/3000^th of the floor area they serve, positioned to encourage through ventilation with one of the permanent ventilators being not more than 600mm above floor level, or

2. where the garage is mechanically ventilated, by providing a system:

   • capable of continuous operation, designed to provide at least 2 air changes per hour, and

   • independent of any other ventilation system, and

   • constructed so that two-thirds of the exhaust air is extracted from outlets not more than 600mm above floor level

[joe90]

Do you intend to put a motor vehicle In it?, if not don’t call it a garage, however workshops are not included in VAT return fir new builds!!!,!