Quick U-building (QUB) is a method for short time measurement of energy performance of buildings, typically one night. It uses the indoor air temperature response to the power delivered to the indoor air by electric heaters. This paper introduces a method for estimating the expected measurement error as a function of the amplitude and the time duration of the input signal based on the decomposition of the time response of a state-space model into a sum of exponentials by using the eigenvalues of the state matrix. It is shown that the buildings have a group of dominant time constants, which gives an exponential response, and many very short and very large time constants, which have a small influence on the response. The analysis of the eigenvalues demonstrates that the QUB experiment may be done in a rather short time as compared with the largest time constant of the building.

快速U建筑物（QUB）是一种用于短时测量建筑物能量性能（通常是一晚）的方法。它利用室内空气温度对电加热器传递给室内空气的功率的响应。本文介绍了一种方法，该方法根据状态空间模型的时间响应分解为指数总和，并利用输入信号的特征值，根据输入信号的幅度和持续时间来估计预期测量误差。状态矩阵。结果表明，建筑物具有一组占主导地位的时间常数，该常数给出指数响应，以及许多非常短和非常大的时间常数，它们对响应的影响很小。