As a property investor it is always great to know how rental rates and vacancy rates nationally are impacting your investment.

The June 2014 RP Data Quarterly Rental Report covering the first half of 2014, has seen house rents remain unchanged across the combined capital cities and a 2.4 percent increase in unit rents.

Annually, house and unit rents across the capital cities have increased by 2.4 percent.

The combined capital city median rents for units rose by 1.2 percent to $420 a week for the June quarter and the median house rent remained steady at $430 a week.

Sydney recorded the largest increase in median unit rent of 2.0 percent. Melbourne unit rents also recorded an increase of 1.4 percent.

The capital cities with the largest gains in median unit rents over the calendar year so far are Hobart with a 3.7 percent increase and Sydney with an increase of 3.1 percent.

The market is experiencing more demand for units for lifestyle and affordability reasons.

These results show that the median weekly rentals for units is now fast approaching or exceeding that of houses in many capital cities.

Although almost all capital city median weekly housing rents remained unchanged during the June quarter, nationally the housing rental market has seen a 1.3 percent growth to $400.

On a year-to-date view, Adelaide was the only capital city to experience an increase of 1.5 percent in median weekly housing rents.

The slowdown in the rental housing market for the June quarter could be a reflection of the growing demand for housing highlighted by increasing sales volumes and therefore reducing the pressure on rental rates.

In regards to vacancy rates, Real Estate Institute of Australia (REIA) March quarterly report recorded falls in rates across a majority of the capital city markets.

The lowest vacancy rates recorded for any capital city market was Sydney at 1.4 percent of rental properties vacant and then followed by Brisbane at 2.3 percent.

There are several contributing factors that have influenced the subdued rental growth that most investors should know. These are the stimulus from low interest rates, low returns on other asset classes and from savings accounts.

The combination of these factors have lured prospective new home owners into buying and eased the demand for rentals.

Capital city rents have experienced moderate growth in the past five years, with capital city unit rents up 2.8 percent annually and capital city house rents up 2.7 percent annually.

Residential property investment for rent is a popular investment strategy and the latest figures suggest it is a more lucrative opportunity than ever.