How LONG DOES IT TAKE TO BUILD A SWIMMING POOL in central texas

This is going to vary by 400% or more depending on the company you choose to build your pool and the requirements of any HOAs or municipalities that will be involved, weather, access and the size and complexity of the project.
Let me start by saying that construction a swimming pool on your property is not process you want to rush. That being said, a fairly simple pool or pool spa, in perfect conditions, can be completed in about 3 months. Although we at Accredited Pools Inc. have accomplished in era of Covid, For simi basic pool projects we tell our clients to expect about 4 ½ months as many things, mostly weather, effect completion times. The high-volume pool companies in our area are taking 17 months from signing to completion. Too many unsuspecting homeowners pay a large deposit to companies or individuals come dig a hole then never come back seriously effecting completion times. We completed 3 pools for customers last year that were started and abandoned by the pool contractor and contacted by several others with this situation. By the time the homeowners exhausted all attempts to get the project completed and accepted that it was not going to happen and get someone to complete it, the project took well over a year  

ACCESS AND WEATHER
Much of the time, the access to the pool location is across the grass and along the side of the house. If the access space is narrow smaller equipment will be needed to dig and remove the spoils adding to the construction time. When you add rain to the mix, the saturated ground will create a big mess causing property damage if you try to run heavy equipment, trucks, trailers, etc. back and forth in these conditions. It may take 3 or 4 days for the ground to dry out enough to continue work so if it rains every 3 or 4 days it can really lengthen the overall construction time.

SCOPE OF WORK
It is not a good idea to plaster a pool before other work like patios. pergolas casitas and especially landscaping as dust and other elements from the process of completing them can permanently stain the pool plaster and totally mess up the water chemistry. We have many projects that include outdoor kitchens, extensive decking and retaining walls, fireplaces, and landscaping. We will dig and construct the pool shell, do the tile and coping and any concrete work, then complete all other work including landscaping. Only then will we plaster the pool, fill it with water and start it up.
Depending on the complexity of the other amenities included in the project, the completion times are extended accordingly

Permits inspections
If your pool requires permits, inspections and or HOA approval, construction times are extended in proportion to the efficiently of the municipality. One of our local municipalities the City of Lakeway takes much more time and effort to obtain the permits than to actually build the pool.
Availability of materials
In recent times the availability of various materials and equipment have been problematic extending completion times and disrupting schedules. Hopefully we will see less of this in the future with covid related issues decreasing.