A rear addition on a San Jose ranch house takes fourteen to twenty-two weeks on site and the family almost always lives through it. Moving takes a weekend and changes everything else. Neither is wrong. When planning an addition, the decision has very little to do with construction and a great deal to do with the lot, the street and the next ten years. These are the questions we ask, in the order we ask them.
About the lot.
- How much yard is behind the house, and do you use it? A 400 square foot suite needs roughly 20 by 20 feet, plus a four-foot rear setback. On a 6,000 square foot lot with a pool, that is usually the whole lawn.
- Where does the sun come from? An addition on the south or west side of the house takes the afternoon light from the rooms behind it. We walk the yard at 4 p.m. before we draw anything.
- Is there a protected tree within fifteen feet? If so, the foundation becomes piers and the schedule grows by about two weeks.
- Could the addition go up instead of out? A second story keeps the yard but needs the existing foundation checked. On 1950s slabs that is a core sample and an engineer's letter; about one in four passes without new footings.
About the house.
- What is the electrical service? A 100-amp panel will not carry a new suite with a heat pump. Plan on a panel upgrade, which the utility schedules four to eight weeks out.
- What is the roof pitch and material? Matching a 4:12 composition roof is routine. Matching a clay tile roof from 1948 means sourcing reclaimed tile, which can take a month.
- How many bathrooms, and where is the sewer lateral? A suite on the far side of the house from the lateral means a trench across the slab. Possible, not pleasant; about a week of work.
- Will the rest of the house still make sense? This is the question that decides it. If adding a primary suite leaves three small bedrooms sharing one 1950s bath, the family is still living in the old plan with one good room attached.
About the next ten years.
- Do you want to stay on this street? Said out loud, the answer is usually immediate.
- Who is the house for in 2036? Children leave; parents arrive. A ground-floor suite with a wide door is an addition that keeps working.
- Can you live through it? Fourteen to twenty-two weeks with a sealed dust wall, a crew on site from 7:30 to 4:30, and no yard. Most families can. Some would rather not, and that is a fair answer.
- What would you do with the house you'd buy? If the answer is "remodel the kitchen and add a bath", you are describing the same project with a longer commute.
What the answers tend to say.
Of the families we walked through these questions last year, about six in ten built the addition, two in ten moved, and two in ten did something smaller: a kitchen, a bath, a wall taken down. The Rose Garden family on our projects page answered question nine before we finished asking it. They had planted the tree in the backyard. The suite went on the other side of the house.
The build is the easy part. The decision is the work, and it is worth an hour of questions before a single drawing.
If you would like to walk through the twelve with us, the first visit is an hour and there is nothing to sign.