Style, location and budget. Settle these three and choosing a builder goes surprisingly fast.
Building a tea room becomes much easier if, before deciding which company to ask, you first put just three of your own wishes into words.
[1] Style — a sōan (a small, closed room of wabi), a hiroma (a bright room for welcoming guests), or ryūrei (whisking tea at a table with chairs). Your sense of size is settled here.
[2] Location — renovating a room in the main house, building a free-standing room in the garden, or including a semi-outdoor roji path. The scale of the work changes with this.
[3] Budget and timing — tea rooms generally start from a few million yen and take several months to build. Deciding a ceiling and a 'by when' keeps a builder's proposals from drifting.
Note these three down, and share them when you contact a company you like, and you'll avoid off-target proposals.
Talk to a builder
Find a company by region and style, and reach out.