Scoring factor
How to weight home age
Home age is year built, nothing else. It is not a style score and it is not an inspection. Weight it when the era of the house is something you are willing to pay for. Otherwise it double-counts the same year that condition already uses.
How hard to weight it
The commute preset is the one that takes age seriously, at 25, next to a 35 commute weight: a newer house and a shorter trip. The investor preset uses 15. Most other presets keep it under 10, because condition already moves with the same year.
A weight of 25 makes the jump from a 4-year-old house (score 100) to a 40-year-old house (score 60) worth 10 points on the total. That is a real reorder. A weight of 5 makes the same jump worth 2 points.
If you want an older house, a high age weight works against you for anything under 100 years. From 30 to 99 years the score only sits between 70 and 50. You are not rewarded for preferring a 1920s house until it crosses 100.
What the weight does to the total
A house under 5 years scores 100. A house of 40 years scores 60. A house of 99 years scores 50, and a house of 100 years scores 100.
| Weight | Effect on the total |
|---|---|
| Weight 25 | New versus 40 years is a 10-point gap. The century jump is a 12.5-point gap against a 99-year-old house. |
| Weight 15 | New versus 40 years is 6 points. Noticeable beside value, not in front of it. |
| Weight 5 | The same new-versus-40 gap is 2 points. Age is recorded and rarely decides. |
The property score is the weighted sum: each factor score times its weight, divided by 100. Weights are scaled to add up to 100 before that sum.
What the score uses
By default an analysis uses the formulas in “What the score uses.” The new scoring engine runs only when FEATURE_USE_NEW_SCORING_ENGINE is on, or when a rollout percentage includes that account. Where that engine differs, it is called out separately. A missing input scores 50. That is a neutral, not a zero, and it can outrank a known weak result.
Age is the current calendar year minus year built. Under 5 years scores 100, under 10 scores 90, under 20 scores 80, under 30 scores 70, under 50 scores 60, and under 100 scores 50.
At 100 years the formula changes to 50 + (200 − age) ÷ 2, capped at 100. A house that is exactly 100 scores 100. A house that is 150 scores 75. A house that is 200 scores 50. The “historic bonus” peaks at the 100-year line and then fades. A 99-year-old house is still on the ordinary scale and scores 50, so one birthday can double the factor.
No year built scores 50. The default engine and the new engine use the same age bands. The new engine does not add census data to this factor.
under 5 years → 100
under 10 → 90
under 20 → 80
under 30 → 70
under 50 → 60
under 100 → 50
100 or older → min(100, 50 + (200 − age) ÷ 2)
No year built → 50
When the new engine is on
The enhanced path scores home age the same way. Neighborhood age is not part of this factor. It shows up only as a possible 5-point bump on condition, and only when that engine is on.
The public overview is the methodology page. Where that page says comparables, orientation, or documented updates, the formulas on this page are the ones that run.
Tradeoffs against the other factors
- Condition and systems
Both factors are functions of year built. Raising both is raising the same fact twice. A house under 5 years scores 100 on age and 95 on condition. A house of 50 years scores 50 on age and 45 on condition. On the investor preset (age 15, condition 25) that is 7.5 plus 12.5, or 20 points of the total, from one field.
- Lot size
The larger lots are often on the older houses that this factor scores at 50 until they hit 100. A buyer who wants a yard and a new house is asking the ranking to do something the local stock may not offer.
- Value
New construction that scores 100 on age is often the expensive side of value. If you weight both highly, only a new house that is also cheap per foot will lead.
Mistakes that move the ranking
- Expecting a renovation to change the age score. A gutted 1920 house is still old. Condition will not credit the renovation either, because it is the same year.
- Treating the historic bump as “old houses are good.” It applies at 100 years, not at 80, and a 99-year-old house scores like a 60-year-old one.
- Weighting age to stand in for systems. The bands are different. Use condition for the maintenance question, and keep age for whether you care about the era.
Profiles that lean on this
The other six factors
Set the weight yourself
The builder opens on an even split, or on the platform default if one is saved. It does not assume this factor. If you want a whole profile filled in, start from a buyer preset.
Build your analyzer