We have lived in our home for over 25 years (home was built in 1992) and have no plans to move for a long time.

In that time, our cars have lived outside due to the fact that the internal, double garage is on the small side, making it a skinny shimmy to access the rear door when both cars are in.

The concrete slab is part of the house slab but has a 100mm step down. The ceiling height is the same as the internal living space, so 2500 given the additional 100mm.

The ceiling space above has been insulated and the three exterior walls are single brick.

Over the years it’s been used as an informal rumpus room for our children (now grown and left home). We painted the brick walls with exterior grade paint, painted the concrete floor with paving paint and threw down a big area rug with some furniture and a TV.

During this time we have not had any water/damp issues.

Now we would like to convert the space to an indoor/outdoor room and used as an entertaining space with lounge seating. No plumbing is planned.

The rear wall of the garage adjoins our covered patio so plan to replace the back wall with aluminium stacker glass doors. We would like to replace the internal sliding pocket door with two glass shaker style doors and have had quotes for supply and installation from a specialist company for this and this will require adding beams for structural reasons.

As our home faces north, where the existing garage roller doors are (two single doors), we intend to build two ‘fake’ carriage style garage doors with horizontal windows at the top to let in light, so from the outside it will still have a garage type appearance from the street.

Eventually, we would like to build a fly over style carport in front for our cars as we feel this will add to the home’s resale value.

Apart from the changes mentioned, and some electrical work to supply lights, ceiling fan and a split system air conditioner, the only other change would be laying vinyl plank on the floor and we plan to do this ourselves.

My questions are around certification and eventual resale of the property with these changes made.

I phoned our council who informed that as we are not changing the existing footprint, we don’t need council approval but need to contact a building certifier.

My neighbour employed a builder to convert his garage into an office - the builder informed him certification is not required if the space is less than 40 square metres - our space is 36.

Can somebody please clarify the process around this, approximate costs and explain the steps required. If we simply just do it ourselves, will it be a problem when it comes time to sell in the future?