Sunroom square footage

Sunroom square footage 200

Quality Tier

Standard materials, solid craftsmanship

Scope of Work

3-season sunroom (screened/basic glass)$57.00/sqft 4-season sunroom (insulated, HVAC)$133.00/sqft Solarium (full glass roof & walls)$190.00/sqft Prefab sunroom kit$7,600 Foundation (slab or piers)$17.10/sqft HVAC mini-split (4-season)$4,300 Electrical (outlets, lighting)$1,700 Interior finishing (flooring, trim)$14.25/sqft Permit & engineering$1,400

Labor

Labor portion of total cost 40%

Sunroom Addition Cost in Modesto: 2026 Guide

Use the calculator above to get a quick estimate. The guide below explains what drives sunroom addition costs in Modesto and what to expect from contractors in Modesto.

Typical Sunroom Addition Costs in Modesto

Project Scope	Low	High
Small 3-season room (100–150 sqft)	$5,000	$9,200
Average 3-season (200 sqft)	$14,200	$35,600
4-season room (200 sqft, insulated)	$35,600	$42,800
Large 4-season / solarium (300+ sqft)	$42,800	$114,000

What Affects Sunroom Addition Costs in Modesto?

Labor rates: Contractors in Modesto charge $43–$86/hour for sunroom addition work — slightly below the national average.

Material costs: Material prices in the West region are slightly below national average due to local supply, transportation costs, and market demand.

Project complexity: Site conditions, permitting requirements, and non-standard layouts can add 15–30% to total project cost.

Frequently Asked Questions

How much does a sunroom addition cost in Modesto?

Sunroom additions in Modesto cost $14,200–$114,000. A basic 3-season room (200 sqft) runs $14,200–$9,200. A 4-season heated/cooled sunroom costs $9,200–$42,800. A full solarium with glass roof can reach $114,000. Prefab kits start around $8,000–$15,000 but require a prepared foundation.

3-season vs. 4-season sunroom — what's the difference in Modesto?

A 3-season room has screened or thin-glass walls with no HVAC — comfortable spring through fall but unusable in winter in Modesto. A 4-season room has insulated walls, double-pane windows, and a mini-split system — livable year-round and often counts as conditioned square footage, adding more home value.

Does a sunroom add home value in Modesto?

A 4-season sunroom typically returns 50–70% of its cost at resale in Modesto. A well-built sunroom adds livable square footage, improves natural light, and has strong buyer appeal. 3-season rooms return less (30–50%) since they're seasonal.

Do I need a permit for a sunroom in Modesto?

Yes — sunrooms are permanent structure additions and require a building permit in virtually all jurisdictions in Modesto. You'll need architectural drawings for a 4-season room. Processing typically takes 2–6 weeks. Your contractor should handle the permit application.

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Estimated cost in Modesto

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Sunroom Addition Cost Calculator — Modesto