Frequently Asked Questions

Yes, there are impact fees that go toward parks, streets, and police. Homeowners can use the Impact Fee Calculator to get an estimate of these fees.

No. Casitas may share utilities with the primary structure. Existing utilities may require replacement for accommodating the additional demand.

Any structure either being constructed as a casita or converted to a casita is required to be permitted and meet building and zoning codes, including setbacks. If you need relief from setbacks, you need to go through the Design Development Option (DDO), which requires you to meet findings related to privacy, noise, light, and for surrounding property owners within 100 feet to be notified for comment.

For a casita to be owned separately from the main house, the lot would need to be split into two. The two new lots must both meet minimum lot size requirements, which are 7,000 square feet in R-1 and 5,000 square feet in R-2, and R-3, to name a few common residential zones. Once the lot with the casita was split off, the casita would no longer be an accessory unit. It would become the primary residence.

Yes, casitas can be built within HPZs and NPZs. Historic Preservation Zone, Historic Landmark (HL) and Neighborhood Preservation Zone design standards and review process continue to be required in those areas. This means that a casita proposed within an HPZ, HL or NPZ must comply with the design standards and review process of the district where it is proposed to be built.

That depends on any regulations put in place by your HOA, often referred to as Covenants, Conditions and Restrictions, or CC&Rs. These are private agreements that are, in general, more restrictive and applied in addition to zoning. For example, a property may be allowed to develop a casita per their zoning classification, but if their HOA prohibits them, they would be in violation of their HOA regulations if they were to develop a casita.

If this is a barrier for homeowners who wish to build a casita, homeowners can advocate for their HOA to modify existing CC&Rs using the prescribed process for changes.

Plans in the Casita Model Plan Library that do not have a "pending approval" indication have been reviewed by Planning and Development (PDSD) staff for compliance with the International Building Code, Unified Development Code, and green building and energy efficiency standards.

Members of the public can browse the gallery, choose a design, and connect with the designer who can confirm fees and next steps to prepare a site plan necessary to get a construction permit.

When a homeowner chooses a pre-approved Casita Model Plan, they will benefit from a streamlined permitting process and reduced permit fees.

Please review the Casita Regulations page to determine if your property is eligible for a casita.

Model plans have been reviewed and approved by building staff. Making changes will require review and therefore no longer qualify as using a model. Homeowners may work with designers of model plans to develop something that meets their needs, but this new plan is required to go through a full review by building staff with the time and costs associated with that process.

The fee to license listed on the library is to use the design for a single site. The designer retains ownership over the design, and the homeowner pays the fee to use the plan one time. The fee to license is determined by the designer of the model plan. The prices listed on the library are subject to change and should be confirmed with the designer by the homeowner.

No. The licensing fee is paid to the designer for use of their plan. The fee listed on the Casitas in Tucson website it subject to change. Please connect with the designer to verify the licensing fee.

No. This is the cost that the designer has set to use the plan one time for a single application.

No. A site plan must be submitted before a permit can be issued. The proposed site plan shows utility line locations and sizes for serving the ADU. Include connection points to existing utility lines and any replacement of existing undersized components.

Permit fees are not waived. The construction document review fees are waived. This is because if a homeowner is using a model plan, those plans have already been reviewed by our staff. Staff still need to review the site plan, which does incur a fee. The actual permitting and impact fees still apply.

Yes, a permit for "residential model off temple" is part of the fast lane, so the permitting process is expected to be 15 days while a new building permit is approximately 30 days.

All new residential buildings in Tucson need to be in alignment with the 2018 International Residential Code (IRC), local amendments, and City of Tucson adopted design ordinances.

Please note: Tucson building codes are updated on a six-year cycle in order to remain current. Designs submitted after the adoption of the new code cycle must be in compliance with the updated building codes.

The Inclusive Home Design Ordinance is a visitability code that provides guidance for all newly built dwellings in the City of Tucson for minimum accessibility criteria such as lever-type door hardware and zero-step building entry.

The installation of solar panels is not required but must be prepared for in the future if not included. Reserving roof space and electrical service capacity for future panel installation. Review the Solar Readiness Ordinance for specifics on how to meet the solar readiness requirements. The electrical should be designed as if the casita has its own electrical service for model plan design purposes. This will facilitate the plan review process and can be revised when a site plan is submitted to reflect using the existing electrical service of the primary residence as necessary.

If a design can be built with variations such as being a studio, a one-bedroom, or two-bedroom, each design must be submitted and have unique permit numbers.

To be added to the Casita Model Plan Library, designers must have their permit number(s). Please complete the submission form. Note that there are additional fields to complete below the MOA if your design has multiple options.

Yes. These designs are reviewed and approved by the State of Arizona. Designs that have received an Arizona certification for a modular building can be included in the Casita Model Plan Library.

A separate egress plan is not required for ADU plans. However, every casita must include at least one exterior swinging door 36" wide and include emergency escape and rescue openings are required for all sleeping rooms. Rescue openings may be a door or a window but must have a clear opening of no less than 5.7 square feet, no less than 24 inches in height, no less than 20 inches in width, with a maximum height of 44 inches above the floor.

An engineer is required if the casita design includes:

*A beam of more than 20 ft
*Any free-standing walls greater than 7ft in height
*Retaining walls retaining 3ft of earth or more

Pre-fabricated trusses must come with an engineered design from the truss manufacturer and the design must be reviewed by PDSD or another licensed designed professional prior to installation. Please review the truss policy.

Mechanical, electrical, and plumbing (MEP) work are all included in a single building permit for single family residences and casitas. A complete construction plan is required that includes structural, architectural, accessibility, energy conservation, electrical, plumbing, and mechanical.

The MEP drawings must be fully detailed and provided as part of the model plan submittal. Strictly speaking, the residential code is prescriptive in nature, so a licensed design professional is not typically required. However, as these model plans will be available to the public, it may be in the designer's best interest for a licensed architect to prepare and stamp the submittal.

Yes, a complete panel schedule, circuit designation, and riser diagram are required.

A One Line Diagram or a riser diagram may be used.

Yes, all exterior lighting must conform with the Outdoor Lighting Code (OLCC). Model plans will not include a lighting calculation but must include the fixture type, location, lumens, and color temperature (Kelvin). The 2012 OLC is the currently adopted lighting code at this time. Please be advised that this code is currently undergoing revisions.

New residential dwellings are required to include heating and cooling. The mechanical load calculations used to properly size the system must be included in the initial submittal, but they do not need to be completed by a licensed professional. REScheck from the Department of Energy can be used to complete the energy calculations and other proprietary software may be used for the mechanical system design.

A model plan must include plumbing fixture unit schedule and water supply calculation to establish the minimum diameter of the water supply piping from the water meter. When a site plan is submitted, the size of the water meter and total developed length of water supply piping must be shown. For casitas that share a water meter with its primary dwelling, all the fixtures in both buildings must be included in the water supply calculations and demand schedule.

Model plans are valid for one year and may be renewed until the residential codes are updated (every six years or sooner). After a new building code is adopted, model plans may not be renewed but will remain valid until their established expiration date.

Yes, the design firm may charge for the use of the pre-approved plan. The dollar amount of the fee charged is up to the design firm. We do request that the fee amount be provided to the City for participation in the Casita Model Plan Library and that cost will be shown on the City's website.

Here you can find the step-by-step guide for using Tucson Development Center online.