The design is a critical part for us too, we have enlisted an architect design our 4 layouts.

But living in the same but different layout town home, we know what it might need for rehab.

We only have a house or two, we say.And just because we got away with not having a professional layout when we got the mortgage for our first rental or even second rental, we think it's okay just to present a mortgage company, bank or hard money lender, just some figures written down on a piece of paper or on an Excel Spread Sheet.But what happens when the time comes when you want to really expand.

@Pierre-Luc AllieThe layout should work fine. 

In this case, I changed the kitchen layout, adding veggie sink to the island, while moving the main sink and dishwasher to an outside wall.

They stayed warm due to generating lots of heat internally and only heating the portions of the house being used {i.e. you would not heat the dining room or salon during the night}.With older properties we usually lay-out a plan to improve the building envelope first through air sealing (getting rid of drafts and convection within the wall cavities) and, where possible, insulation {not always straight forward ... many old brick buildings have limited insulation options due to the brick requiring heat transfer from inside to drive moisture from the brick}.Around here it is not uncommon to find an old mansion converted to multiple units - or the occasional purpose-built multi-unit - where the operating costs are 70 - 80% of the revenue and heating comprises 20 - 25% of the operating costs.  

My wife handled all layout changes, decor, finishes and colors.

It is just a carefully planned process.Bought a 2 bed 1 bath layout in Leimert Park (average price point as of Jan 2023 is $1M), remodeled the existing 1924 craftsman bungalow plus added a 3/4 bathroom/HVAC/200amp panel.

Growing up in the contracting business, I intend to find something that we can build some equity into immediately, then rent it out to one or possibly two families if the layout allows for an accessory apartment. 

Comes with tenants who have been there 2 years and pay on time.2nd Unit: Previously rented for $950. 2-3 bedroom unit, but with unconventional layout.