Unfortunately, there is not currently a facility, within the software, to link a rental property and its income to a SIPP. This is something that has been requested previously, however, and it may be something we are able to add in the future.
In the meantime, the SIPP is treated as a pension with investment holdings and the property within it is simply one possible asset class. As things stand, therefore, we recommend that you enter the SIPP via the Pensions > Money Purchase screen (as normal), in order to ensure that the appropriate rules are applied relating to crystallisation and annuitisation. One would, then, incorporate the current value of the investment property into the total current balance of the account.
With regard to annual growth/income returns, we would suggest that you consider how much the property, and its income, adds to the overall value and annual capital growth of the SIPP account and set the fixed growth rate of the SIPP accordingly - i.e, you will need to estimate the 'blended total return' on the account by adding the property’s assumed appreciation rate to the growth rate of any other asset classes within the portfolio - the total return, of course, will incorporate the income/yield that is earned from the property.
A SIPP worth £1 million has a rental property worth £750,000 with income of 5%, and capital growth of 3% so total return on the property is 8%. Other assets in the SIPP are worth £250,000 and have a total return of 5%.
Blended total return is (((£750,000 x 8%) + (£250,000 x 5%)) / £1,000,000) x 100 = 7.25%
Alternatively, if using market assumptions, set the asset allocation with the appropriate percentage of property-based assets.