Aspen historic commissioners ask council to clarify TDRs, update design guidelines for wildfire and energy rules

The Historic Preservation Commission and Aspen City Council used part of an April 13 work session to review transferable development rights (TDRs) and to seek council support for updates to the city’s historic design guidelines.

Planning staff reported that Aspen’s TDR program began with Ordinance 54 in 2003 and that 135 certificates have been issued at 39 sending sites; staff said 68 certificates have landed on receiving properties and 62 reported valuations range from about $153,000 to $700,000 with an average near $274,818. ‘‘Over the life of the program, we’ve had 135 certificates issued at 39 unique properties,’’ Planning Director Dan Folk said while showing a map of sending and landing sites.

Commissioners and councilmembers raised questions about whether the program’s incentives — floor‑area bonuses plus the ability to sever and sell TDRs — unintentionally move development pressure from historic neighborhoods into other parts of town. Council members asked staff to provide better data on how many potential sending sites remain and whether cash‑in‑lieu or TDR proceeds have been spent in the neighborhoods that experienced the impact.

HPC Chair Cara Thompson and staff noted two common TDR pain points: lack of clear maximums for how many certificates can be severed for some properties and unclear interaction between FAR bonuses and TDR severance. Thompson said the program ‘‘really does help development sites where you have a large historic house that takes up most of the footprint,’’ but also urged clearer parameters where the code reads ambiguously.

On design guidelines, Historic Preservation staff and commissioners asked for an update to address wildfire resiliency, evolving energy‑code requirements (for example, how to insulate historic walls without stripping siding) and better guidance on mass and scale for mixed‑use and multifamily areas where affordable housing is being encouraged. ‘‘We need to study that and also look more into how we can achieve better fire ratings,’’ Thompson said.

Councilmembers expressed willingness to begin conversations about trade‑offs and directed staff to return with options and recommended language. The HPC also asked for more staff capacity — commissioners said the program currently has one primary staff member and that institutional memory has been lost with recent turnover; council acknowledged resource constraints but agreed to keep the item on the work‑session agenda for further action.

No formal votes were taken; staff will follow up with data requests and proposed code or guideline amendments.