Top Regret in Custom Homes is 'Insulation, Airtightness, and Energy Saving'. Nearly 33% Would Prioritize Housing Performance if Rebuilding

What 'Unexpected' Things Lurk in the Dream Home?

A custom home is often said to be a once-in-a-lifetime purchase.

While you have the freedom to decide the floor plan and specifications, it seems there are quite a few instances where people feel, 'I wish I had changed this,' after they start living in it.

What are the details of daily life that are hard to notice during the design stage, and the challenges that become apparent over a long period of living?

Therefore, we recently collaborated with 'Ichikawa Kenchiku-ten', a custom home and renovation company in Sanjo City, to conduct a survey on 'Regrets and Unexpected Things in Custom Homes' among 120 men and women nationwide who answered 'I have experience building a custom home' in a preliminary screening.

* When quoting the contents of this press release, please take the following actions:

- State that the source is a 'Survey by NEXER Inc. and Sanjo City Custom Home/Renovation Company Ichikawa Kenchiku-ten'.

- Set a link to Ichikawa Kenchiku-ten (https://www.ichikawakenchikuten.com/).

Survey Overview: 'Questionnaire on Regrets and Unexpected Things in Custom Homes'

Survey Method: Internet Questionnaire

Survey Period: May 7 - May 14, 2026

Survey Targets: Men and women nationwide who answered 'I have experience building a custom home' in a preliminary screening

Valid Responses: 120 samples

Question Contents:

Question 1: Are there any points you regret and think, 'I wish I had changed this,' after building your custom home?

Question 2: What are the specific contents of your regrets? (Multiple choices allowed)

Question 3: Were there any 'unexpected' things you noticed after living there? (Multiple choices allowed)

Question 4: Please tell us the specific situation of the most unexpected thing.

Question 5: Were there any regrets or unexpected things regarding construction costs or budget? (Multiple choices allowed)

Question 6: What is the point you would say, 'If I were to rebuild my house, I would change this'? (Multiple choices allowed)

Question 7: Please tell us the point you most want to change and the reason for it.

* As a general rule, percentages are rounded to the first decimal place, so the total may not equal 100%.

36.7% Answered They 'Have Regrets' About Building a Custom Home

First, we asked if there were points they regretted and thought, 'I wish I had changed this.'

As a result, 36.7% answered 'Yes,' and 63.3% answered 'No.'

While over 60% answered they have no regrets, it is clear that about 40% feel regret about some aspect of their home building.

Next, we asked those who answered 'Yes' about the specific contents.

The most common response was 'Insulation, airtightness, and energy-saving performance' at 31.8%.

This was followed by 'Floor plan and room layout' at 27.3%, and 'Location and number of outlets/switches,' 'Bath/toilet specifications,' 'Soundproofing/noise reduction performance,' and 'Garden/exterior/parking lot,' all at 18.2%.

Items related to the basic performance of the house ranked at the top.

Additionally, regrets are seen in items that directly affect daily livability, such as the floor plan, outlet placement, and plumbing specifications.

Because there are many parts that can be freely decided in a custom home, it might be easier for points where one feels 'I should have done this better' to emerge after starting to live there.

15.8% Answered the Unexpected Thing After Moving In was 'Location/Number of Outlets Doesn't Match Needs'

Next, we asked about 'unexpected' things noticed after moving in.

Excluding 'Other,' the most common answer was 'Location and number of outlets do not match needs' at 15.8%.

This was followed by 'Insufficient or hard-to-use storage' and 'Summer heat/winter cold is more than expected,' both at 9.2%, and 'Utility bills are higher than expected' at 8.3%.

Where to place appliances and the daily living flow are parts that are quite difficult to imagine on a blueprint.

It is apparent that there are many cases where people first realize 'I wanted one here' only after they begin living in the house.

We also asked about specific situations, so here are a few introductions.

Please tell us the specific situation of the most unexpected thing.

- The summer heat is harsh, and it's hot unless you turn on the air conditioner in every room. (Female, 40s)

- Because winter is colder than I thought. (Female, 40s)

- The living noise in the atrium is loud. (Female, 40s)

- Too much light enters from the windows. (Female, 30s)

- The sales person told me there was almost too much storage, but in reality, it's not enough. (Female, 30s)

- Fallen leaves come in, making cleaning difficult. (Male, 30s)

- There are surprisingly few windows. (Female, 20s)

From the responses, a 'gap between imagination and reality' emerges in areas essential to living, such as the thermal environment, lighting, and storage. Elements that look attractive during the design phase can sometimes create different challenges once you live there.