1. Project Summary
We are looking to add a prefabricated Caretaker Dwelling Unit (CDU) on a mountain property near Aspen, CO. Pitkin County has confirmed the CDU is allowed, with a maximum of 1,000 sq ft of living area total across all free-standing structures. The county looks favorably on pre-manufactured/modular structures. We are seeking quotes from vendors who can deliver a unit to this site — 2BR/2BA minimum, 3BR/2BA preferred.
2. Site Conditions
| Elevation | 7,296–7,318 ft (per topographic survey by Aspen Survey) |
| Terrain | ~20 ft elevation change across property (slopes west to east) |
| Build location | Road-side (west) of property, within defined Activity Envelope, 15–20 yards from road |
| Current condition | Bare land — no existing foundation or pad at proposed build location |
| Exposure | Unsheltered — full exposure to weather and snow |
| Water feature | Roaring Fork River along east boundary — 100 ft stream setback (CDU will be on opposite side) |
| Lot size | ~2.23 acres (AR-10 zone, legally non-conforming/grandfathered) |
| Existing structures | 2-story wood frame house (~2,108 sq ft), shed, gravel parking area |
Critical: Road Access. Twining Flats Rd is a narrow paved road with a very tight turnaround and a 60-ft right-of-way. Vendors must confirm delivery feasibility for this route. Full-size semi with wide-load may not be feasible. Panelized or dual-module delivery may be required.
3. Structure Requirements
Size & Layout
| Total living area | 1,000 sq ft maximum (county-mandated CDU cap) |
| Bedrooms | 2 minimum, 3 desired. Please provide floor plans for both. If 3BR requires dropping the living room, show us that option. |
| Bathrooms | 2 full (minimum) |
| Kitchen | Non-negotiable — must have a kitchen. Full kitchen or kitchenette acceptable, but cannot be removed to gain a bedroom. |
| Porch | Front porch desired |
| Garage | Not part of this project (separate structure, separate budget) |
Design & Aesthetic
| Style | Mountain modern |
| Roof | Slanted/pitched only — no flat roofs. Standing seam metal preferred. |
| Aesthetic matching | Not required to match existing primary residence |
| Interior finish level | Mid-grade |
Engineering Requirements
| Snow load | Must be rated for 80–100+ PSF ground snow load (Pitkin County mountain site at ~7,300 ft) |
| Wind load | Per Pitkin County building code |
| Energy code | 2021 IECC |
| Frost protection | 36 inches |
| Outdoor design temp | -16°F |
| Ice dam barrier | Required — must extend 4.5 ft inside exterior wall line |
| Roof covering | Class A minimum |
| Building code | 2021 ICC codes with Pitkin County amendments |
Construction & Delivery
| Construction type | IRC/IBC modular strongly preferred (not HUD-code manufactured) |
| Colorado approval | Must carry Colorado Division of Housing insignia or be approvable in Colorado |
| Delivery method | Multi-module or panelized acceptable. See road access alert above. |
| Foundation | Vendor should recommend type based on site slope and soil conditions |
| Heating system | Flexible — vendor's recommendation for this site and budget |
4. Existing Utilities
| Water | Well on property (Basalt Water Conservancy District). Capacity TBD — new well may be needed. |
| Electricity | Available on-site |
| Septic | Existing system for primary residence. New septic required for CDU. |
| Gas | Natural gas confirmed on property — can be routed to CDU |
| Internet | Available on property |
5. Budget
| Total all-in budget | ~$600,000 (CDU only — garage is separate) |
| Includes | Structure, site work, septic, possible well, foundation, utility hookups, delivery, installation |
| Flexibility | Budget is flexible — an extra $100K is fine if the unit is significantly nicer |
| Est. site work | $100,000–$200,000+ (Pitkin County costs) |
| Est. structure budget | $300,000–$500,000 (after site work) |
Quote request: Please break out the structure cost separately from any site work, foundation, or utility costs you would handle. We need to understand how much of the budget is consumed by site prep vs. the dwelling itself. This project is not heavily budget-constrained — quality and fit matter more than finding the cheapest option.
6. Timeline
| Land use approval | ~6 months (full special review, Pitkin County) |
| Assignment cycle | Applications assigned once/month |
| Prefab production | 3–6 months (can overlap with land use approval if vendor selected early) |
| Ideal completion | ~12 months from application submission |
| Urgency | Not urgent, but bedrooms are the priority (baby coming) |
7. Permitting Context
- CDU confirmed by Pitkin County (calls 3/30 and 3/31/2026) — 1,000 sq ft max living area
- Special review required (~6 months) for detached CDU on non-conforming lot
- Deed restriction required — occupancy limited to employees or immediate family
- No architect required for land use application (Rebecca, Planner of the Day, 3/31)
- Modular homes treated same as site-built under Colorado law (IRC/IBC plans submitted to CO Division of Housing)
- Foundation designed by CO-registered professional required for modular placement
- No HOA or restrictive covenants
8. Dimensional Requirements (AR-10 Zone)
| Max height — accessory structure | 20–21 ft to ridge; 12 ft to eave |
| Front setback | 30 ft (lots ≤ 3 acres) |
| Side setback | 20 ft |
| Rear setback | 30 ft |
| Stream setback | 100 ft (Roaring Fork River) |
| Floor area budget remaining | ~3,642 sq ft of 5,750 max (after existing house) |
9. What We Need From You
- Feasibility confirmation — Can you deliver to a narrow mountain road with a very tight turnaround near Aspen?
- Colorado approval status — Do you carry CO Division of Housing insignia, or can you obtain it?
- Snow load engineering — Can your structure be engineered for 80–100+ PSF ground snow load?
- Itemized quote — Structure cost separate from site work, foundation, delivery, and installation
- Floor plan options — 2BR/2BA and 3BR/2BA configurations within 1,000 sq ft, with pitched roof. If 3BR requires trading the living room, show us that layout.
- Timeline estimate — From order to delivery-ready
- Scope of work — What do you handle (turnkey) vs. what requires a local GC?
10. County Contacts
| Planner of the Day | 970-429-6108 / planneroftheday@pitkincounty.com |
| Builder of the Day | builderoftheday@pitkincounty.com |
| OWTS / Septic (Bryan Daugherty) | 970-319-3799 |
| Community Development | 970-920-5526 |
| Permit system | sagesgov.com/pitkincounty-co |
Little Annie CDU Project — Vendor Specification Sheet — April 2026
Questions: Contact Jon Deutser at
jondd@att.net or
713-898-6744