A second home
on the same lot.
Designed to be legal.

That is the first question and it is answered against your specific address, because rules differ sharply between municipalities here. Lot size, setbacks, coverage, height and sometimes parking all bear on it, and some communities do not permit them at all. We check before any design work begins.

Almost every jurisdiction caps ADU size, often as a percentage of the main house or as a fixed maximum, and lot coverage frequently binds before the cap does. The honest answer comes from your survey and your zoning, not from a rule of thumb.

Sometimes, and it is worth checking. The shell already exists and coverage is usually established. But you inherit the ceiling height and structure, and bringing an existing garage up to habitable standards - including current wind requirements - can cost more than people expect.

Usually yes. Most jurisdictions define a dwelling unit as needing its own cooking facilities, and a kitchenette may not qualify. It also makes the difference between something you can let and a large guest room. We confirm your local definition first.

Yes, and it is worth designing for it explicitly: a level entry decided before the slab is poured, a step-free shower, blocking behind the tile for grab bars, and door widths that still work with a walker. All of that is far cheaper now than retrofitted.

Often, and it is frequently what makes a constrained lot work - a bedroom above without adding footprint. The constraint is ceiling height: a loft is only habitable space if it genuinely complies, and height limits also apply to the building overall.

For a new structure, effectively yes. Setbacks, coverage and easements are measured against a real survey, not estimated from a plat or an aerial image.

Some jurisdictions require an additional space for an ADU, some waive it, and some do not require one. It can meaningfully change the site layout, so it is confirmed early.

Always. It is a new dwelling, so it is fully permitted work with structural, electrical, plumbing and mechanical review, and multiple inspections through construction.

Sometimes a scheme can be reshaped to comply - that is usually the better path. Where it cannot, a variance may be possible, but it is a separate process with its own timeline and no guaranteed outcome. We will tell you honestly which situation you are in.

Many communities have their own rules on accessory structures and some prohibit them outright. Board approval is separate from the building permit and runs on the board's schedule, so it is worth starting early.

Yes. There will be short planned interruptions to power and water when services are connected, and the build area is fenced and separated.

The build footprint plus the access route to it. The route is the part most likely to need making good afterwards, and it is agreed with you before anything arrives.

Because an ADU is a whole building and two of the biggest cost drivers - what the zoning permits and whether services can reach it - are unknown until the lot is reviewed. A figure before that is a guess.

In rough order: extending electrical capacity, long drainage runs, difficult site access, a second level, required parking, and any variance process. Finishes matter far less than people assume.

After the final inspections pass and the permit is closed. A new dwelling cannot lawfully be occupied before that, and we will not hand over keys sooner.

It is a whole additional building envelope - its own roof, its own services, its own systems. Budget for it the way you budget for the main house, proportionally.

Sometimes, depending on the jurisdiction and the utility. Where it is allowed it makes letting the unit considerably simpler, and it is much cheaper decided at design than retrofitted.